BBC Sky at Night - September 2021

FINDING THE FIRST BLACK HOLE COLLISIONS

How gravitational wave astronomy is coming of age

Sky at Night#196SEPTEMBER2021

THE TELESCOPES DARK SKIES

THAT CHANGED ON YOUR

ASTRONOMY DOORSTEP

Discover the instruments that Top sights for long
have revolutionised the way nights this autumn
we see the Universe
and winter

METROPOLIS CAREERS ABOVE
ON THE MOON THE CLOUDS

Observe the 'streets' of A students' guide to getting

Gruithuisen's lunar city ahead in the thriving space sector

A PLANETARY PUZZLE INCONSTANT LIGHT EYEPIECE NOT INCLUDED

Solving the mysteries of The best variable stars to On test: the telescope you

Solar System formation track in late summer don't need to look through

YOUR
PERSONAL
TOUR GUIDE
TO THE
GALAXY

IMAGINE discovering stars, planets and deep Model shown StarSense Explorer DX
sky objects in real-time whilst also being able 102AZ RRP £379.99 (phone not included)
to accurately identify what you can see.
AWARD WINNING StarSense sky technology Other models available: StarSense Explorer DX 130AZ, DX 6"
enables you to use your smartphone with this
telescope, to do just that. SCT, DX5" SCT, LT 70AZ, LT 80AZ, LT 114AZ and LT 127AZ
VIEW incredible detail through the 102mm
objective lens with our special high
transmission XLT optical light coatings.
PERFECT for observing brighter objects in
the City and even more from Dark Sky Sites.

For more information visit celestron.com/ssetelescopes Contact Celestron at [email protected]

HOW TO CONTACT US

Welcome Subscriptions, binders and back issues
03330 162119*
Mon–Fri 9am–5pm

*Calls from landlines will cost up to 9p per minute. Call
charges from mobile phones will cost between 3p and
55p per minute but are included in free call packages.
If calling from overseas, please dial +44 (0)1604 973727

Celebrating the telescopes Editorial enquiries +44 (0)117 300 8754
that have changed astronomy 9:30am–5:30pm, Mon–Fri
Advertising enquiries +44 (0)117 300 8145
:KHQ *DOLOHR UHFRUGHG KLV PDJQLƅHG REVHUYDWLRQV RI WKH 0RRQ DQG
WKH SODQHWV ZLWK D PRGLƅHG QHZ 'XWFK LQYHQWLRQ WKH WHOHVFRSH KH Print subscription enquiries
FRXOG KDUGO\ KDYH IRUHVHHQ WKH UHYROXWLRQ LQ XQGHUVWDQGLQJ KH KDG www.buysubscriptions.com/contactus
VHW LQ PRWLRQ 7RGD\ D OLWWOH RYHU \HDUV VLQFH WKH *DOLOHDQ PRRQV Digital subscription enquiries
ZHUH ƅUVW REVHUYHG WKH WHOHVFRSH KDV HQDEOHG XV WR VHH EH\RQG WKH www.buysubscriptions.com/contactus
YLVLEOH VSHFWUXP DQG EDFN WR WKH SULPRUGLDO FRVPRV 7XUQ WR page 26 Editorial enquiries
WR UHDG (]]\ 3HDUVRQŝV FHOHEUDWLRQ RI WKH LQVWUXPHQWV WKDW KDYH [email protected]
SHUKDSV GRQH PRVW WR ZLGHQ WKH ERXQGDULHV RI RXU XQGHUVWDQGLQJ

Subscription enquiries
,WŝV ZRUWK WUDLQLQJ \RXU RZQ WHOHVFRSH RQ WKH VNLHV WKLV PRQWK DV UK enquiries: FREEPOST IMMEDIATE MEDIA
the nights start to lengthen. On page 32 6FRWW /HYLQH ORRNV DW WKH (please write in capitals)
GDUN VN\ VHDVRQ WR SUHYLHZ WKH WUHDWV WKDW OLH LQ VWRUH IRU ELQRFXODU Overseas enquiries: PO Box 3320,
DQG QDNHG H\H VWDUJD]HUV DV ZHOO DV REVHUYHUV DW WKH H\HSLHFH 3 Queensbridge, Northampton, NN4 7BF, UK
Editorial enquiries
:LWK WKH DGYHQW RI JUDYLWDWLRQDO ZDYH DVWURQRP\ WHOHVFRSHV FDQ BBC Sky at Night Magazine, Immediate Media
QRZ REVHUYH RXWVLGH WKH HOHFWURPDJQHWLF VSHFWUXP WR EUHDN QHZ Co Bristol Ltd, Eagle House, Bristol, BS1 4ST
ground. On page 62 *RYHUW 6FKLOOLQJ ORRNV DW SODQV IRU WKH ODWHVW
LQVWUXPHQW WR REVHUYH PLQXWH FKDQJHV LQ JUDYLW\ WKH (LQVWHLQ BBC Sky at Night Magazine ISSN 1745-9869 (USPS XXXXX) is
7HOHVFRSH DQG KRZ LW ZLOO UHYROXWLRQLVH RXU YLHZ RI KLJK HQHUJ\ published monthly by Immediate Media Co Bristol Ltd., Eagle House,
HYHQWV DFURVV WKH 8QLYHUVH Bristol, BS1 4ST, United Kingdom. The US annual subscription price
is $155.88. Airfreight and mailing in the USA by agent named World
7KH (LQVWHLQ 7HOHVFRSH LV MXVW RQH H[DPSOH RI PDQ\ LQ D WKULYLQJ Container Inc, 156-15, 146th Avenue, 2nd Floor, Jamaica, NY 11434,
VSDFH VHFWRU SXVKLQJ DKHDG ZLWK QHZ RSSRUWXQLWLHV ,I \RXŝUH USA. Periodicals postage paid at Brooklyn, NY 11256.
FRQVLGHULQJ D MRE RU TXDOLƅFDWLRQ LQ VSDFH VFLHQFH WHFK RU
HQJLQHHULQJ WKLV LVVXH +D\OH\ 6PLWK RI WKH 1DWLRQDO 6SDFH $FDGHP\ US POSTMASTER: Send address changes to BBC Sky at Night
ORRNV DW VRPH RI WKH URXWHV WR WDNH WR VHW XS D FDUHHU LQ WKLV DUHD Magazine, World Container Inc, 156-15, 146th Avenue, 2nd Floor,
DQG WKH SDUW WKDW *&6(V $ /HYHOV DQG XQGHUJUDGXDWH VWXGLHV SOD\ Jamaica, NY 11434. Subscription records are maintained at
Turn to page 36 IRU PRUH DQG IRU 7LP 3HDNHŝV WLSV RQ JHWWLQJ DKHDG Immediate Media Bristol Ltd., Eagle House, Bristol, BS1 4ST
United Kingdom.
Enjoy the issue!
Become an Insider
Chris Bramley, Editor
7KH PRUH ZH NQRZ DERXW ZKDW \RX OLNH
PS Our next issue goes on sale on Friday 17 October. the better placed we are to bring you
WKH EHVW PDJD]LQH SRVVLEOH 6R ZHŝG OLNH
WR LQYLWH \RX WR MRLQ RXU RQOLQH UHDGHU SDQHO Ŝ,QVLGHUVŝ
Just log on to www.immediateinsiders.com/
register WR ƅOO RXW WKH VKRUW UHJLVWUDWLRQ VXUYH\ DQG
ZHŝOO EH LQ WRXFK IURP WLPH WR WLPH WR DVN IRU \RXU
RSLQLRQV RQ WKH PDJD]LQH DQG RWKHU UHOHYDQW LVVXHV

Sky at Night – lots of ways to enjoy the night sky…

Television Online Social media Podcasts Tablet/phone eNewsletter

Find out what The Visit our website Follow us on Twitter, Listen to our Radio Get each month’s The best targets to
Sky at Night team for competitions, Facebook and Astronomy podcasts issue on your Apple observe each week,
have been exploring astrophoto Instagram for space where the magazine or Android device, delivered to your
in recent and past galleries, observing news, astro images team and guests now with bonus inbox. Visit bit.ly/
episodes on page 16 guides and more and website updates discuss astro news image galleries skynewsletter

Find out more at: www.skyatnightmagazine.com

September 2021 BBC Sky at Night Magazine 3

26

CONTENTS C = on the cover

Features Regulars Reviews
6 Eye on the sky 86 Unistellar eVscope eQuinox C
26 Telescopes that 10 Bulletin 90 Founder Optics FOT106
C changed astronomy 14 Cutting edge C
16 Inside The Sky at Night triplet refractor
The instruments that have had 18 Interactive 94 Books
the biggest impact on astronomy 21 What’s on 96 Gear
23 Field of view
COVER MAIN IMAGE (BACKGROUND): ADVENTURE_PHOTO/ISTOCK/GETTY IMAGES. THIS PAGE: 36 So you want to work 24 Subscribe to BBC Sky The Sky Guide 16-PAGE
TMT INTERNATIONAL OBSERVATORY, NASA, © GOOGLE, © NIKHEF, @THESHED_PHOTOSTUDIO, C in space? 44 Highlights CENTRE
STOCKTREK IMAGES, INC./ALAMY STOCK PHOTO, UNIVERSITY OF BATH, BBC, MARY MCINTYRE at Night Magazine PULLOUT
What students need to know to 32 Explainer EXTRA C
prepare for a career in space 74 DIY Astronomy 46 The big three C
98 Q&A: an aerospace engineer
60 Google’s astronomy Doodles 48 The planets
Astrophotography
Space sketches that made us smile 76 Capture 50 September’s all-sky chart
78 Processing
62 The next step in gravitational 80 Gallery 52 Moonwatch
C wave astronomy
53 Comets and asteroids
How will the Einstein Telescope
pick up black hole collisions? 53 Star of the month

68 Late summer variables 54 Binocular tour

C Get to know your changing stars 55 The Sky Guide challenge

56 Deep-sky tour

58 September at a glance

4 BBC Sky at Night Magazine September 2021

New to astronomy? Extra content

To get started, check out our guides and glossary at ONLINE
www.skyatnightmagazine.com/astronomy-for-beginners
Visit www.skyatnightmagazine.
36 com/bonus-content/582H4HJ/
to access this month’s selection
of exclusive Bonus Content

SEPTEMBER
HIGHLIGHTS

The world’s largest radio telescope

Astrophysicist Carole Mundell on how the Square
Kilometre Array will reveal the secrets of the cosmos

60

62

86 68 Watch The Sky at Night: Make a model of our
ET and the BBC celestial neighbours
This month’s contributors
Maggie and Chris look Download our cosmic
back at how the BBC has distance calculator to
reported on the search for help with this month’s
extraterrestrial life over stellar DIY Astronomy
the past few decades. project (see page 74).

Mary McIntyre Govert Schilling Hayley Smith The Virtual Planetarium

Outreach astronomer Astronomy journalist Space educator Pete Lawrence and Paul Abel guide us through
the best sights to see in the night sky this month.
“This model “I love the “Ground-
was great Einstein breaking September 2021 BBC Sky at Night Magazine 5
fun to build. Telescope, VFLHQWLƅF
I have as there’s a discoveries,
never seen chance that upcoming
our nearest stellar this gravitational wave Moon and Mars
neighbours presented observatory will be built missions... Space is an
in this way before and in my home country: exciting industry to
, ORYH WKH ƅQDO UHVXOW Š WKH 1HWKHUODQGV Š EH SDUW RI Š Hayley
Mary builds a 3D Govert reports on advises prospective
model of our Sun how astronomers will GCSE and A-Level
and its closest stellar monitor black hole students aiming for
neighbours, page 74 collisions, page 62 the stars, page 36

6 BBC Sky at Night Magazine September 2021

CONCERTO DEBUT

A new tool begins scanning for signals from the early
Universe, when the first generation of stars were born

APEX/VISTA, 6 JULY 2021

Looking more like a hawk bearing down on 7KH VLJQDO IURP WKH UHLRQLVDWLRQ SHULRG ESO/J. EMERSON/VISTA ACKNOWLEDGMENT: CAMBRIDGE
its prey than its usual close resemblance to Ś PLOOLRQ WR ELOOLRQ \HDUV DIWHU WKH ASTRONOMICAL SURVEY UNIT
a feline foot, this is the Cat’s Paw Nebula Big Bang – is so minute that it calls for a
DV LPDJHG IRU WKH ƅUVW WLPH E\ &21&(572 QHZ REVHUYLQJ WHFKQLTXH FDOOHG LQWHQVLW\
PDSSLQJ 7KLV PHDVXUHV WKH VLJQDOV IURP
&21&(572 ZKLFK VWDQGV IRU &DUE21 &,, WKH PDVVHV RI XQUHVROYHG VRXUFHV LQ RUGHU
OLQH LQ SRVW U(LRQLVDWLRQ DQG 5HLRQLVD7L2Q WR HYDOXDWH WKHLU FXPXODWLYH HPLVVLRQ DW D
epoch (we’ll just stick with the acronym), JLYHQ DJH RI WKH 8QLYHUVH
is the brand new instrument on board the
(XURSHDQ 6RXWKHUQ 2EVHUYDWRU\ŝV PHWUH 7KH SLQN DQG ZKLWH WRQHV IURP
GLDPHWHU $3(; $WDFDPD 3DWKƅQGHU &21&(572ŝV GDWD DUH FRPELQHG KHUH
([SHULPHQW WHOHVFRSH ZLWK QHDU LQIUDUHG GDWD IURP (62ŝV
9,67$ WHOHVFRSH
Bringing both imaging and spectroscopy
to the table, it has begun scanning the sky MORE ONLINE
at frequencies between infrared and radio
ZDYHV LQ VHDUFK RI WKH UDGLDWLRQ HPLWWHG A gallery of these and more
by ionised carbon atoms – signatures from stunning space images
WKH HDUOLHVW GD\V RI WKH FRVPRV

September 2021 BBC Sky at Night Magazine 7

VIRGIN GALACTIC/HANDOUT/ANADOLU AGENCY, X-RAY: NASA/CXC/LEIDEN UNIV./A. BOTTEON ET AL./RADIO: LOFAR/ U Virgin berth
ASTRON/OPTICAL/IR:PANSTARRS, ESO/PHANGS, COURTESY OF NASA/SDO AND THE AIA/EVE AND HMI SCIENCE TEAMS
VSS UNITY, 11 JULY 2021
:KHWKHU KH RIƅFLDOO\ UHDFKHG VSDFH RU QRW 1$6$
ZKLFK GHƅQHV LW DV NP ZRXOG VD\ \HV \HDU ROG
6LU 5LFKDUG %UDQVRQ KDV ZRQ WKH ŜELOOLRQDLUH VSDFH UDFHŝ
EHFRPLQJ WKH ƅUVW WR KHDG VN\ZDUGV LQ KLV RZQ FUDIW
7KH 966 8QLW\ URFNHW SODQH FDUULHG SDUW RI WKH ZD\ E\
PRWKHUVKLS 906 (YH SURSHOOHG KLP DQG ƅYH RWKHUV
WR NP DERYH (DUWK ZKHUH WKH\ H[SHULHQFHG IRXU
PLQXWHV RI ZHLJKWOHVVQHVV $ PDMRU VWHS WRZDUGV KLV
SODQV WR SXW VXERUELWDO VSDFHƆLJKW ZLWKLQ WKH UHDFK RI
DQ\RQH ZLWK D VSDUH LW SLSSHG -HII %H]RVŝV
1HZ 6KHSDUG ODXQFK E\ QLQH GD\V

Slingshot or slosh? Z

CHANDRA X-RAY OBSERVATORY/PAN-STARRS/
LOFAR, 15 JULY 2021
$ WLWDQLF FODVK EHWZHHQ WZR JDOD[\ FOXVWHUV HDFK
FRQWDLQLQJ KXQGUHGV RI JDOD[LHV KDV SURGXFHG DQ
XQXVXDO HIIHFW LQ $EHOO ; UD\ RSWLFDO DQG UDGLR
REVHUYDWLRQV UHYHDO DQ HQRUPRXV SLQN MHW IURP D
VXSHUPDVVLYH EODFN KROH D IDLQWHU ƅODPHQW EHORZ LW DQG
Ś FOHDUO\ VKRZQ E\ WKH ; UD\ GDWD LQVHW Ś D VSLUDOOLQJ
/ VKDSHG SOXPH 7KLV LV WKH FXUYHG WDLO RI KRW JDV
VWULSSHG IURP WKH VPDOOHU FOXVWHU E\ WKH EUXLVLQJ
HQFRXQWHU ZKLFK LV WKRXJKW HLWKHU WR KDYH RYHUVKRW WKH
FROOLVLRQ DQG ŜVOLQJVKRWWHGŝ WR WKH VLGH RU LV ŜVORVKLQJŝ
EDFN DQG IRUWK LQ WKH JUDYLWDWLRQDO WXVVOH

8 BBC Sky at Night Magazine September 2021

MUSE looks for clues Z

VERY LARGE TELESCOPE, 16 JULY 2021
6ZLUOV RI JORZLQJ UHG K\GURJHQ UHYHDO WKH UHJLRQV ZKHUH
QHZ VWDUV DUH EHLQJ PLQWHG LQ VSLUDO JDOD[\ 1*&
7KLV LV RQH RI FORXGV RI ZDUP JDV H[DPLQHG
E\ WKH 086( 0XOWL 8QLW 6SHFWURVFRSLF ([SORUHU
LQVWUXPHQW DWWDFKHG WR &KLOHŝV 9/7 DV SDUW RI WKH
3+$1*6 SURMHFW DQ LQWHUQDWLRQDO SXVK WR GLVFRYHU
ZKDW WULJJHUV DQG ZKDW KROGV EDFN QHZ VWDU IRUPDWLRQ

V Flares are back

SOLAR DYNAMICS OBSERVATORY, 3 JULY 2021
6'2 KDV VSRWWHG LWV ƅUVW ; FODVV ƆDUH RI WKH QHZ VRODU
F\FOH WKHVH DUH WKH ELJJHVW FODVV RI ƆDUH DQG E\ IDU WKH
ODUJHVW H[SORVLRQV LQ WKH 6RODU 6\VWHP 7KH VPDOOHU
FODVVHV DUH $ % & DQG 0 HDFK OHWWHU UHSUHVHQWLQJ D
IROG LQFUHDVH LQ HQHUJ\ RXWSXW RYHU WKH ODVW 6HYHUDO
% DQG & DQG RQH 0 FODVV ƆDUH ZHUH VSRWWHG DURXQG
WKH VDPH WLPH ZLWK PDQ\ PRUH H[SHFWHG DV 6RODU &\FOH
EXLOGV WRZDUGV VRODU PD[LPXP SUHGLFWHG LQ

September 2021 BBC Sky at Night Magazine 9

The latest astronomy and space news, written by Ezzy Pearson

Comment

by Chris Lintott

NASA/ESA/STSCI/JULIANNE DALCANTON (UW) IMAGE PROCESSING: ALYSSA PAGAN (STSCI, NASA/JPL/SPACE 2QH RI WKH ƅUVW LPDJHV FDSWXUHG E\ +XEEOH 7KH ƅUVW LPDJHV
SCIENCE INSTITUTE, ALMA (ESO/NAOJ/NRAO)/BENISTY ET AL, ESA/ATG MEDIALAB (inset) after its recent repairs was of taken with Hubble’s
ARP-MADORE 0002-503, a large spiral restored cameras
galaxy located 490 million lightyears away were of two
unusual galaxies,
Hubble resumes its observations as part of a survey
of irregular systems
NASA recalled Hubble’s original builders to help fix the problem led by Julianne
Dalcanton.
$IWHU VSHQGLQJ ƅYH ZHHNV RIƆLQH WKH \HDU ROG to uncover the solution to Hubble’s malady.
Hubble Space Telescope is back in action and ş7KDWŝV RQH RI WKH EHQHƅWV RI D SURJUDP WKDWŝV Earlier this year
observing the cosmos. observations made
been running for over 30 years: the incredible with Hubble
“I’m thrilled to see that Hubble has its eye back on amount of experience and expertise,” says Nzinga revealed the
the Universe, once again capturing the kind of images Tull from Goddard Space Flight Center, who led surprising extent
that have intrigued and inspired us for decades,” the recovery efforts. “There’s so much dedication of Andromeda’s
says NASA administrator Bill Nelson. “This is a to their fellow Hubble teammates, the observatory gaseous halo and
moment to celebrate the success of a team truly and the science Hubble is famous for.” that quasars have
dedicated to the mission.” been captured in
%\ PLG -XO\ WKH WHDP KDG LGHQWLƅHG WKDW WKH LWV GHHS ƅHOGV
A problem with the telescope’s payload computer, problem lay in the power control unit (PCU). A Closer to home,
which controls the science instruments, placed the protection circuit had triggered – either due to planetary nebulae
telescope into safe mode on 13 June. Initial attempts degradation or the PCU drawing the wrong and stars have
to restart the system and switch to a backup failed. voltage – and turned off the power. On 15 July, been scrutinised
To continue troubleshooting the problem, NASA the team was able to switch over to a back-up by the space
called in retired staff members who had helped build PCU and by 17 July, Hubble was back in business, telescope.
the space telescope in the 1980s and combed PDNLQJ VFLHQWLƅF REVHUYDWLRQV RQFH DJDLQ
through 40-year-old documents by hand, attempting hubblesite.org This variety is
why everyone is
so relieved to have
Hubble back. It’s
a supremely
multipurpose
instrument, as
capable of
contributing to
cosmology as
astrobiology. Let’s
hope there’s plenty
more life in the old
scope yet.
Chris Lintott
co-presents
The Sky at Night

10 BBC Sky at Night Magazine September 2021

NEWS IN

BRIEF

Cracks on the icy surface of the moon Enceladus
may be the result of tides in the water below
created by Saturn’s gravitational pull

Enceladus shakes with ‘icequakes’

Cracks in the moon’s surface could hint at what’s beneath ILLUSTRATION

Icequakes could rumble across the surface of Earth,” says Mark Panning from the Jet ESA rover ready
icy moon Enceladus, created by the tidal forces Propulsion Laboratory.
of Saturn’s gravitational pull. The hypothesis An upgraded parachute to
comes from a recently published study that ([DPLQLQJ WKH VHLVPLF SURƅOHV RI D ZRUOG enable the British-built
compared stress fractures seen on the moon of offers an insight into its internal structure: in the Rosalind Franklin rover to
Saturn with similar features found on Earth in case of Enceladus whether it has a subsurface land safely on Mars has
the Ross Ice Shelf in Antarctica. liquid water ocean – an environment that could passed its high-altitude
be habitable. Such icequakes could also create tests, meaning the rover
“The study represents a key way of cracks large enough for subsurface water to should be ready for launch
investigating what seismicity on Enceladus and escape, creating the water jets that have been in 2022. Problems with
other tidally activated icy worlds may look like, seen erupting through Enceladus’s icy crust. the original 35m-wide
E\ ORRNLQJ DW WKH EHVW DQDORJXHV ZH FDQ ƅQG RQ www.jpl.nasa.gov parachutes caused a delay.

Moon nursery seen clearly for the first time Alien artefact search

A group of astronomers
have announced a new
endeavour, the Galileo
Project, to hunt for extra-
terrestrial technological
civilisations (ETCs). The
project will search for
physical artefacts from
ETCs, including interstellar
objects, such as ‘Oumuamua
which passed through the
Solar System in 2017.

Þ The disc around exoplanet PDS 70c has enough material to form three Moon-sized satellites Gamma ray burst
fires on queue
7KH ƅUVW clear detection of a swirling discs of material that resolution that we could
potential moon-forming disc can go on to form moons, but clearly identify that the disc is An unusual type of star,
around an exoplanet has been have struggled to differentiate associated with the planet known as a gamma
made by the Atacama Large them from the larger dust and we are able to constrain UHSHDWHU HPLWWHG LWV ƅUVW
Millimeter/submillimeter Array discs that create the planets. LWV VL]H IRU WKH ƅUVW WLPH Š burst after three months
(ALMA). The disc is around the of inactivity on 24 June, as
Jupiter-like planet PDS 70c “Our work presents a clear Though over 4,000 predicted. If it follows the
and has enough mass to create detection of a disc in which exoplanets have now been pattern seen so far, the star
three moons, each with the satellites could be forming,” found, almost all of them are (SGR 1935+2154) will emit
same mass as Earth’s Moon. says Myriam Benisty, an mature systems. The discovery random bursts for the
astronomer from the University of infant systems will help next four months, as
Astronomers have long of Grenoble who led the study. astronomers learn how these astronomers attempt to
thought that newly formed “Our ALMA observations were planets and their moons grow. study the phenomenon.
planets are surrounded by obtained at such exquisite www.almaobservatory.org

September 2021 BBC Sky at Night Magazine 11

BULLETIN

Þ Richard Branson (top left), Virgin Galactic’s Sirisha Bandla (above) and Jeff Bezos (top right) enjoy the views at the edge of space

Space tourism takes flight

The passenger flights captured the world’s attention, garnering both praise and criticism

VIRGIN GALACTIC, BLUE ORIGIN, GL ARCHIVE/ALAMY STOCK PHOTO, The billionaire IRXQGHUV RI VSDFHƆLJKW KDOI KRXU ƆLJKW WKDW XVHG D FRPELQDWLRQ “When you look out at the planet, there
NASA/GODDARD SPACE FLIGHT CENTER, GIUSEPPE PARISI companies Blue Origin and Virgin of conventional jet and rocket engines are no borders. There’s nothing. It’s one
*DODFWLF ƆHZ RQ ERDUG WKHLU VSDFHFUDIWVŝ to reach a height of 86km. planet and we share it, and it’s fragile,”
LQDXJXUDO SDVVHQJHU ƆLJKWV WKLV -XO\ Bezos said, after returning to Earth.
heralding a new age of space tourism. “To all you kids down there, I was once
a child with a dream looking up to the A few weeks later, Bezos announced
-HII %H]RV IRXQGHU RI VSDFHƆLJKW VWDUV Š %UDQVRQ VDLG GXULQJ KLV ƆLJKW ş1RZ Blue Origin was willing to cover up to $2bn
company Blue Origin, announced in June I’m an adult in a spaceship with lots of of the cost of building a second Human
WKDW KH SODQQHG WR Ɔ\ RQ KLV FRPSDQ\ŝV other wonderful adults looking down to Landing System (HLS) for NASA’s future
suborbital crew vehicle, New Shepard, on our beautiful, beautiful Earth. To the next lunar missions, allowing Blue Origin to
-XO\ 7KLV VSXUUHG 9LUJLQ *DODFWLF generation of dreamers, if we can do this, compete with one already commissioned
IRXQGHU 5LFKDUG %UDQVRQ WR PRYH WKH ƅUVW just imagine what you can do.” from Elon Musk’s company SpaceX.
SDVVHQJHU ƆLJKW RI KLV RZQ VSDFH WRXULVP
vehicle, SpaceShipTwo, forward to 11 July, Nine days later, Jeff Bezos blasted off $OWKRXJK WKH SDLU RI SDVVHQJHU ƆLJKWV
ahead of Bezos. RQ D URFNHW SRZHUHG ƆLJKW WKDW ODVWHG mark a pivotal moment in commercial
MXVW RYHU PLQXWHV UHDFKLQJ DQ DOWLWXGH VSDFHƆLJKW WKH\ KDYH DOVR GUDZQ
3DVVHQJHUV RQ ERWK ƆLJKWV H[SHULHQFHG RI NP +H ZDV MRLQHG E\ \HDU ROG criticism. “It’s a momentous day in the
four minutes of weightlessness and a aviation pioneer Wally Funk and 18-year- history of having way too much money...
spectacular view of Earth curving away old Oliver Daemen, whose father spent for the second time in nine days a
EHORZ EXW WKH ƆLJKWV WKHPVHOYHV ZHUH several million dollars on the ticket. billionaire took a joy ride to the ionosphere,”
very different. Branson, accompanied Funk and Daemen are now the oldest said comedian Stephen Colbert.
by three other members of the Virgin DQG \RXQJHVW SHRSOH WR KDYH ƆRZQ LQ www.virgingalactic.com
Galactic team, experienced a two-and-a- space respectively. www.blueorigin.com

12 BBC Sky at Night Magazine September 2021

NEWS IN

BRIEF

Women’s continuing contributions ILLUSTRATION
to astronomy will be celebrated by
the Royal Astronomy Society’s new
medal, named after Caroline Herschel

RAS medal honours women astronomers Living on the edge

The award will alternate between the UK and Germany The smallest, yet most
massive white dwarf ever
A new award, the Caroline Astronomy is currently a 6RFLHW\ DQG KDG D VLJQLƅFDQW observed has been found,
Herschel Medal, has been PDOH GRPLQDWHG ƅHOG RQO\ impact on astronomy, and as packing 1.35 times the mass
created to recognise the 27 per cent of astronomy VXFK LW LV ƅWWLQJ WKDW D QHZ of our Sun into an object
outstanding work of female lecturers and 12 per cent of medal and prize should be the size of the Moon. The
astrophysicists. In honour of professors are female. It is named in her honour,” says star probably formed when
the medal’s namesake, who hoped that the award will Emma Bunce, president of the two smaller white dwarfs
was German-born but lived redress this balance by Royal Astronomical Society, merged, and is right on
in Bath, the medal will be increasing the visibility of who created the medal the limit of how massive
awarded to a UK astronomer women in astronomy. alongside the German such a star can be before
one year, and a German Astronomical Society. going supernova.
astronomer the next. “Caroline Herschel has a ras.ac.uk
profound connection to our Cosmic wanderers

Solar Orbiter spots secret Sun storms The Kepler Space Telescope
has revealed four new
Astronomers can now predict Coronal mass ejections have the IUHH ƆRDWLQJ SODQHWV
the path of ‘stealthy’ solar potential to cause havoc if they’re untethered from a host star.
storms, with the help of ESA’s released in the direction of Earth The telescope found them
Solar Orbiter. Coronal mass by looking at the same star
ƅHOG HYHU\ PLQXWHV IRU
ejections (CMEs) are huge solar two months, hunting for
microlensing signals – where
eruptions that eject particles starlight is bent as it passes
by a planet.
and radiation. If one hits Earth,
Module misses ISS
it can damage power systems
Nauka, the Russian science
and satellites, though these PRGXOH IRU WKH ,66 ƅQDOO\
launched on 21 July,
effects can be mitigated if we over a decade behind
schedule, only for a
know one is coming. CMEs that suspected computer
fault to prevent it docking.
originate near the Sun’s $V RI ZULWLQJ ƆLJKW
controllers were still hopeful
equator form dark and bright the module would be able
to rendezvous with the
patches on the solar surface, Earth to scale ISS at a later date.
but at higher latitudes they

are only visible using a special

instrument called a coronagraph. To remedy the problem Palmerio’s team

“If you see a CME on a coronagraph, you looked at images from the Solar Orbiter, which

don’t know where on the Sun it came from, so ODXQFKHG LQ 7KLV UHYHDOHG D SDWWHUQ RI

you can’t predict its trajectory and won’t know tiny variations that had been invisible to

whether it will hit Earth until it’s too late,” says previous observatories, but which could help

Erika Palmerio from the University of California astronomers track the origin of CMEs.

at Berkeley, who led the study. www.esa.int

September 2021 BBC Sky at Night Magazine 13

Our experts examine the hottest new research

CUTTING EDGE

ILLUSTRATION fourth planet that is about 10 times more massive
than Mars, and also a massive planet in the asteroid
belt. There’s clearly something wrong here.

Gas giants on the rampage

Matthew Clement at the Carnegie Institution for

Science, Washington, DC, and his colleagues argue

that the important detail is when this dynamic

instability arose. Over the past few years they have

performed a series of studies that indicate the Solar

System was thrown into turmoil very early in its

history. Clement’s models work with Jupiter and

6DWXUQ JRLQJ RQ WKH UDPSDJH ZLWKLQ WKH ƅUVW

million years after the Sun’s birth and even before the

ƅQDO DVVHPEO\ RI WKH URFN\ LQQHU SODQHWV ,Q WKLV ODWHVW

study they have run some updated computer models

Scientists have been looking at how Mars of this early instability scenario for the formation of
was impacted by the movement of the the planets. This time they have been focusing
gas giants in the early Solar System VSHFLƅFDOO\ RQ KRZ VHQVLWLYH WKH RXWFRPH IRU (DUWK
and Mars is to shifts in Jupiter and Saturn’s orbits.

Did planetary migration They found that such an early instability in the
orbital architecture of their modelled Solar Systems

invariably truncated the terrestrial disc

stunt Mars’s growth? “The models EH\RQG WKH (DUWK IRUPLQJ UHJLRQ
This stunted the growth of Mars,
producing a planet much like the

work with Jupiter RQH ZH ƅQG 7KH HDUO\ LQVWDELOLW\

The movement of planets in the early Solar and Saturn going also prevented the formation
System could have starved infant Mars on the rampage of a large planet between
within the first Mars and Jupiter, leaving a
W e know the Solar System suitably depleted asteroid
formed about 4.5 billion years
ago from a disc of dense 100 million belt. What’s more, in many of
gas and dust swirling around
the proto-Sun. The gas giant years after the Clement’s model Solar Systems,
planets formed rapidly in Sun’s birth” WKH VLPXODWHG (DUWK HQGHG XS
colliding with another massive

protoplanet – just as is believed to

the cooler, outer region of this protoplanetary disc, have happened to form the Moon.

ZKLOH WKH URFN\ LQQHU SODQHWV ƅQLVKHG DFFUHWLQJ Clement stresses, however, that this is by no

sometime later. What has become increasingly PHDQV WKH ƅQDO ZRUG RQ KRZ WKH 6RODU 6\VWHP ZDV

clear over recent years, however, is that the initial originally formed. These updated models explain a

FRQƅJXUDWLRQ RI WKH SULPRUGLDO 6RODU 6\VWHP ZDV lot that was previously problematic, but they leave

very different, and at some point the gas giant some unanswered questions. For example, these

planets shifted and migrated into their current orbits. models still struggle to reproduce the low orbital

This period of ‘dynamic instability’ would have been HFFHQWULFLWLHV RI (DUWK DQG 9HQXV 7KH FUHDWLRQ RI DQ

NASA, NASA/SAO/CXC/C.JONES ET AL. hugely disruptive to the entire system. For example, Prof Lewis Dartnell LQQHUPRVW SODQHW OLNH 0HUFXU\ LV DOVR GLIƅFXOW 7KHVH
the current best-supported model argues that is an astrobiologist shortcomings, says Clement, are outstanding
our planetary system actually formed with one or at the University problems that future planet formation studies will
two additional ice giants (alongside Uranus and of Westminster need to resolve.

Neptune), which were subsequently ejected out of

the Solar System. Lewis Dartnell was reading… The Early Instability Scenario: Mars’ Mass
But we still seem to be missing something Explained by Jupiter’s Orbit by Matthew S Clement et al
Read it online at: https://arxiv.org/abs/2106.05276.
important in our understanding of the formation of

the planets. Many models commonly produce a

14 BBC Sky at Night Magazine September 2021

CUTTING EDGE

An X-ray view of with the galaxy’s central supermassive black hole,
and they appear to have captured cooler gas

the Virgo Cluster associated with stars in the inner regions of the
system, carrying it out into the galaxy.

The other galaxy considered in detail, NGC 4636,

shows what can happen when these processes

A look at what lies beyond the visible Prof Chris Lintott happen on a large scale. Here, gas is being expelled
is an astrophysicist from the galaxy altogether, shocking material in the
can reveal a galaxy’s hidden secrets intergalactic medium and heating it up so it glows

and co-presenter brightly in the XMM image. The observations also

Most elliptical galaxies aren’t much on The Sky at Night reveal the metallicity of the gas – the proportion of
to look at, not much more than
D URXQGHG EDOO RI VWDUV :LGH ƅHOG elements heavier than hydrogen and helium, which,
images of the Virgo Cluster,
a nearby home for many as they are produced by previous generation of stars,
ellipticals, add interest by
showing the sheer number of systems, but “As hot gas provide a guide to how processed by star
each individually is, well, pretty dull. This is,
expelled from formation the gas has been.
galaxies can alter (DFK RI WKH RWKHU JDOD[LHV ZLOO KDYH WKHLU
the environment
own stories to tell. This kind of work in the
DUFKLYHV ZKLFK UHƆHFWV D KXJH DPRXQW RI

of course, appalling bias, typical of a species of neighbouring effort to reprocess and display archived data

(Homo sapiens) from a spiral galaxy which galaxies, or even in a uniform and useful fashion, doesn’t
happens to see with eyes sensitive only to affect them directly, always get enough attention, but catalogues
wavelengths that cover 4,000 to 7,000 like these are the raw materials for future
Ångstroms. Look at these systems with X-ray this is important” science – and it’s also sometimes just fun to look

eyes – or, as Harvard’s Nazma Islam and colleagues at pictures of galaxies, especially when you pick the

do, rummage through the archives of the XMM- right wavelength.

Newton space telescope – and they look different,

with dramatic jets and hot gas swirling around

the brightly glowing black holes at their centres.

The team has assembled an atlas of such

observations (there is a long-standing astronomical

tradition of using ‘atlas’ to mean not a book of maps,

but a collection of images). The galaxies included

have already featured in a similar collection of

observations with NASA’s Chandra X-ray

Observatory, but XMM is a larger telescope,

operating at slightly shorter wavelengths, and

&KDQGUD KDV D VPDOOHU ƅHOG RI YLHZ WKDQ LWV (XURSHDQ

counterpart. While the Chandra observations told

astronomers a lot about what was happening to the

galaxy itself, a broader perspective is needed to

understand how the systems interact with their

surroundings. As hot gas expelled from galaxies can

alter the environment of neighbouring galaxies, or

even affect them directly, this is important.

Take NGC 1550, for example. The Chandra image A Chandra X-ray Observatory image of galaxy NGC
shows a nice, smooth halo of hot gas throughout 4636 reveals arcs of gas extending 25,000 lightyears
PRVW RI WKH JDOD[\ EXW ;00 FRQƅUPV WKH SUHVHQFH into a vast cloud of hot gas that envelopes the galaxy
of a bar-like feature at the galaxy’s nucleus, aligned

roughly east to west. From observations of the

galaxy’s spectrum, we can tell this east to west Chris Lintott was reading… An XMM-Newton Early-type Galaxy Atlas
feature is formed of cooler gas, and it seems to by Nazma Islam et al..
line up with jets that others have seen in radio Read it online at: https://arxiv.org/abs/2106.14937
observation. The jets come from activity associated

September 2021 BBC Sky at Night Magazine 15

The Sky at Night TV show, past, present and future

INSIDE THE SKY AT NIGHT

In August’s Sky at Night episode, Jonathan Nichols reflects on his Þ Scientists are
work with Juno, which has just had its mission extended by four years
learning about
NASA/ESA AND J. NICHOLS (UNIVERSITY OF LEICESTER) X 2, GRANGER F ive years ago, I had the privilege to stand Juno’s principal science goal is to peer beneath Jupiter’s aurorae,
HISTORICAL PICTURE ARCHIVE/ALAMY STOCK PHOTO, BBC in the Rose Bowl stadium in Pasadena, Jupiter’s clouds and reveal the secrets of the planet’s by combining
California, and pose for a photo with interior and the story of its formation, and by the observations
members of the NASA Juno mission extension that of the rest of the Solar System. But taken by the
science and engineering teams just hours its unique orbit passing over the poles has particular Hubble Space
before the spacecraft was due to enter YDOXH IRU P\ ƅHOG RI UHVHDUFK Ś WKH VWXG\ RI WKH Telescope with the
into orbit around Jupiter. The atmosphere in the Jet magnetospheres of the outer planets. Like Earth, the top-down views
Propulsion Laboratory later that evening was thick RXWHU SODQHWV SRVVHVV PDJQHWLF ƅHOGV ZKLFK FUHDWH (inset) taken by
with tension as we awaited the signal that the spectacular auroral emissions. For over 10 years I had the Juno mission
VSDFHFUDIW KDG ƅUHG LWV HQJLQH FRUUHFWO\ $IWHU D observed Jupiter’s aurorae from afar with the Hubble
ƅYH \HDU MRXUQH\ ZH ZHUH SRLVHG WR ƅQG RXW LI WKH 6SDFH 7HOHVFRSH DQG QRZ ZH ZHUH WR JHW D ELUGV H\H
mission that had been years in the planning would view from above the auroral zone. The pictures were
take place – or not. stunning; the science team cheered and clapped
As we now know, the main engine, built by the ZKHQ WKH ƅUVW LPDJHV RI -XSLWHUŝV LQIUDUHG DXURUDH
%ULWLVK FRPSDQ\ 0RRJ 8. :HVWFRWW ƅUHG SHUIHFWO\ from the Jovian Infrared Auroral Mapper (JIRAM)
and cheers of joy greeted the start of what has turned instrument were shown at a meeting: intricate swirls,
out to be an astonishing journey of exploration. arcs and blobs of aurora that were hitherto unseen.

16 BBC Sky at Night Magazine September 2021

THE SKY AT NIGHT WANTS YOUR QUESTIONS

As part of the British Science Festival 2021, The Sky at Night is recording
a special programme on 8 September, when the presenters and special
guests will be answering questions from viewers. If you have a question – on
anything from space travel and technology to astronomy and astrophysics
– you can email it to the programme team at: [email protected]

INSIDE THE SKY AT NIGHT

Jonathan Nichols, A surprise was the form of the Io auroral footprint, ZHUH QRW UHSRUWHG LQ WKH ƅUVW UHVXOWV IURP RYHU WKH
is a Reader at the which is a manifestation of the electromagnetic auroral region, leading to a debate as to what
University of interaction between the rapidly rotating Jupiter and its actually drives Jupiter’s main auroral emissions. More
Leicester, and innermost Galilean moon. The volcanoes of the little recently, by using a combination of Hubble and Juno
member of the moon spew sulphur and oxygen into space, much of data we have shown that the electric currents in the
Juno Science Team which is picked up by Jupiter’s rotating magnetic magnetosphere are increased when the aurorae are
ƅHOG DQG SURSHOOHG DZD\ IURP WKH SODQHW WR IRUP D bright, which, in my view, strongly implicates the
rotating disc of plasma surrounding the gas giant. tug of war is powering the emissions.

The electromagnetic tug of war between Jupiter But Juno’s journey is still underway and has years
and the plasma disc, mediated by millions of amps yet to run. It will be exciting to see the results as Juno
of electric current, has long been thought responsible progresses around to the dusk side of Jupiter’s
for Jupiter’s bright main ring of aurora. However, magnetosphere, which will provide vital information
surprisingly, the signatures of this electric current about the processes which drive Jupiter’s aurorae.

Looking back: SEPTEMBER
The Sky at Night

19 September 1957 Sky at Night: Question Time

On 19 September were delayed 7KLV PRQWKŝV HSLVRGH LV D RQH KRXU VSHFLDO
ƅOPHG OLYH IURP WKH &LYLF 7KHDWUH LQ
1957, Patrick from reporting Chelmsford as part of the 2021 British
Science Festival. Maggie, Chris, Pete and
Moore was joined their discoveries a panel of special guests and astronomy
experts take to the stage in front of a
on The Sky at and so the credit studio audience to answer questions
about the mysteries of the Universe and
Night E\ \HDU instead went to provide practical observing advice.

old Clive Hare, Antonín Mrkos Four, 12 September, 10pm (first repeat
Four, 16 September, 7:30pm)
who had been the IURP WKHQ Check www.bbc.co.uk/skyatnight
for more up-to-date information
ƅUVW SHUVRQ LQ WKH Czechoslovakia,
Þ Maggie, Chris and the panel on stage
UK to spot a new who spotted the
during Sky at Night Question Time in 2019
bright comet comet on 2

– Comet Mrkos. Þ Comet Arend-Roland, as viewed with a August and
In April and sent out an
48” Schmidt-Cassegrain telescope in 1957 Astronomical
May 1957, Comet

$UHQG 5RODQG Ś WKH ƅUVW QDNHG H\H Telegram to inform the community.

comet in several decades – had been The next day, British schoolboy Clive

streaming across the night sky. Now Hare also spotted the comet in a

faded from view, astronomers assumed telescope he’d built himself, but, alas,

there would be a long wait for the next. was too late to claim the discovery.

But then, just a few months later on The reason for so many independent

the morning of 29 July 1957, Japanese sightings was that Comet Mrkos, as it

astronomer Sukehiro Kuragano spotted became known, approached from such

what appeared to be another comet an angle that it was hidden as it

streaming across the sky. A few days approached the Sun. It was only when it

afterwards pilot Peter Cherbak also passed the Sun that it could be seen, by

VSRWWHG WKH VDPH REMHFW ZKLOH Ɔ\LQJ which point it was already a bright and

over Nebraska. Unfortunately, both fully active comet.

September 2021 BBC Sky at Night Magazine 17

Emails – Letters – Tweets – Facebook – Instagram – Kit questions

INTERACTIVE

Email us at [email protected] MESSAGE
OF THE
MONTH

This month’s top prize: Inspired by the gas giants

two Philip’s titles About two years, while on a night shift, one of
my colleagues showed me two dots in the sky,
The which turned out to be Jupiter and Saturn. At
‘Message that moment I realised how much is actually in
of the Month’ writer will the night sky and that inspired me to see what
receive a bundle of two top else was out there.
titles courtesy of astronomy
publisher Philip’s: Heather $ IHZ ZHHNV ODWHU , ERXJKW P\ ƅUVW WHOHVFRSH
Couper and Nigel Henbest’s and I got hooked on stargazing after looking at
2021 Stargazing and Robin the Moon. (It also made me look into many of
Scagell’s Guide to the the space missions, including Apollo, Voyager
Northern Constellations and Cassini.) It amazes me that something so
far away can be seen so large and in so much
Winner’s details will be passed on to detail; it really puts into perspective how small
Octopus Publishing to fulfil the prize we are and how far away everything is.

I can’t wait until Jupiter and Saturn come
back around so I can take photos of them.
Jamie Addison, via email

Inspiring words, Jamie! There’s nothing like Þ Jamie’s photo of the Moon, showing the crater
seeing the largest planets in the Solar System
to bring home the true size of the cosmos we Copernicus and Montes Apenninus, as taken with
inhabit. We can’t wait for them to be better a Samsung Galaxy S10+ through an eyepiece
placed either. – Ed

DAILY HERALD ARCHIVE/CONTRIBUTOR/ISTOCK/GETTY IMAGES, RODW/WIKIPEDIA/PUBLIC DOMAIN Tweet Different views each other. Indeed, this is the nature of
astronomy as a science, where there is
Lar McCarthy I’m no scientist but two articles in the July not a final definitive answer, but rather a
#SDUVHF Ť -XO 2021 issue appear to contradict each most widely accepted explanation for
The Dumbbell Nebula, M27, RWKHU 2Q SDJH LQ Ŝ(\H RQ WKH 6N\ŝ WKH the current observations, until more
taken from my backyard ‘We’re nothing special’ caption states that detailed observations come along. In this
#observatory in #Cork #Ireland observations of spiral galaxies like our case the Gaia-Enceladus Milky Way
with a @Celestron & &*(0 own lead scientists to conclude that the collision is currently the more widely
and a @zwoasi 1600MM Pro Milky Way, “…evolved peacefully over accepted theory. – Ed.
Cool through +D DQG 2,,, ƅOWHUV eons,” and “…didn’t come about because
@CorkAstronomy @ of a gigantic mash-up.” But on page 11 in Following the ISS
AstronomyIRL @AstronomyMag ‘Bulletin’, the ‘Stolen stars’ story explains
@skyatnightmag that several of the oldest giant red stars in My name is Billy Herbert and I’m 13 years
our Galaxy “…originally belonged to a old. On Sunday 18 July I watched the
VDWHOOLWH JDOD[\ FDOOHG *DLD (QFHODGXV International Space Station pass over our
which collided with the Milky Way home with my dad and brother Gavin,
billions of years ago.” How are these which was fantastic with clear skies. Then
contradictory conclusions both correct? RQ :HGQHVGD\ WKH VW DW SP ZH
Georgina Gittins, via email observed the space station again, but
this time it was followed by two other
The two pieces of research that we satellites showing the same amount of
light as the space station, looking from
reported on do appear to contradict

18 BBC Sky at Night Magazine September 2021

the ground like they were dock with the space station SCOPE DOCTOR
about 100 to 200 metres on the 29th. – Ed.
apart, going across the sky on Our equipment specialist cures your
the same line until they Space walk optical ailments and technical maladies
disappeared. The last time we
checked, on Thursday 22nd I was intrigued by Mary With Steve Richards
DW SP WKH IROORZLQJ McIntyre’s article (‘Make a
satellites were not there with scale model of the Solar Email your queries to
the space station. Do you System’, August 2021 issue). [email protected]
know what they were? If you want to appreciate the
Billy Herbert, Whitchurch, scale of the Solar System then I have a Sky-Watcher 200PDS and 250PDS
Hampshire do the Somerset Space Walk Newtonian reflector, and an Altair Hypercam
along the Bridgwater and 290C and 183C camera. I tried to take a filtered
Well observed, Billy! It’s likely Taunton Canal. Stretching image of the Sun, but couldn’t capture the whole
the following satellites were over 22km, the Sun and disc. Would a focal reducer help me get it all?
the Russian Nauka laboratory planets are represented in the
module, which has an 11m-long correct proportions in both COLIN ANDERSON
robotic arm on its outside. distance and size of models.
Nauka launched on 21 July to The Sun is at the mid-point The short answer is no! There are two main issues
and the diameter of the >

that make using a focal reducer on a Newtonian

The Somerset Space Walk is UHƆHFWRU XQVXLWDEOH WKH GLIƅFXOW\ LQ REWDLQLQJ IRFXV
centred around the Sun near
Maunsel Lock Tearooms with a camera, and the generation of elongated star

VKDSHV WRZDUGV WKH HGJH RI WKH LQFUHDVHG ƅHOG RI YLHZ

1HZWRQLDQ UHƆHFWRUV DUH UHQRZQHG IRU WKHLU

short back-focus, which makes focusing tricky,

if not impossible, to achieve on some

instruments as the focus tube simply cannot

be moved in far enough. Your two

Newtonians are DS versions, which Þ A focal reducer

means that the length of the optical is unsuitable for a
tube has been slightly shortened and Newtonian like the
the secondary mirror moved closer to Sky-Watcher 200PDS

WKH SULPDU\ PLUURU 7KLV PRGLƅFDWLRQ SURMHFWV PRUH RI WKH OLJKW

cone out through the focuser making camera focus easier to

achieve. But a focal reducer would negate this advantage.

1HZWRQLDQ UHƆHFWRUV VXIIHU IURP FRPD ZKLFK OHDGV WR WKH

JHQHUDWLRQ RI HORQJDWHG VWDUV DW WKH HGJH RI WKH ƅHOG RI YLHZ

which is why coma correctors are often used by imagers.

Unfortunately, a focal reducer would exacerbate this issue

enormously, producing extremely poor shaped stars off axis.

ON FACEBOOK Steve’s top tip

WE ASKED: Who or what has made the greatest What is an eyepiece’s focal length?
contributions to astronomy?
An eyepiece works by adjusting its distance from a telescope’s
Carol Miller For me it has to be NASA’s Voyager missions. focal plane (the point at which light through the scope is
They are amazing. focused) so that a ‘pencil’ of parallel light rays, known as the
exit pupil, enters the pupil of the observer’s eye. When the
Kris Derry Sir Patrick Moore, with his boundless enthusiasm eyepiece is in focus, its focal length is the distance from the
and passion for the subject. scope’s focal plane to the point inside the eyepiece where the
light rays become parallel thanks to being refracted by the lens
Paul Etcell Herschel... Hubble... Hoyle... Hawking... The answer is HOHPHQWV DQG LWŝV XVXDOO\ LQ PLOOLPHWUHV 7KH PDJQLƅFDWLRQ RI
H-based... the telescope/eyepiece combination can be worked out by
dividing the scope’s focal length by the eyepiece’s focal length.
Brian Smale (LQVWHLQ DQG KLV JHQHUDO WKHRU\ RI UHODWLYLW\
Steve Richards is a keen astro imager and an
Christopher James Heather Couper astronomy equipment expert

AR Gavin &RSHUQLFXV Ś KH FKDQJHG WKH WKHRU\ DERXW WKH (DUWK
being the centre of the Universe. It could be said that he laid the
foundations for modern astronomy.

September 2021 BBC Sky at Night Magazine 19

BBC Sky at Night Magazine is published by Immediate INTERACTIVE
Media Company Bristol Limited under licence from
BBC Studios, which helps fund new BBC programmes. Instagram

EDITORIAL astrojackmn • 17 July

Editor Chris Bramley NGC 7000 – the North America Nebula!
Art Editor Steve Marsh ,W IHHOV JUHDW WR KDYH UHYLVLWHG WKH ƅUVW
Production Editor Neil McKim target I ever shot and I have come
News Editor Ezzy Pearson away with an image that shows I have
Staff Writer Iain Todd improved. I love this target as it is
Reviews Editor Paul Money so large and bright and has such a
distinctive shape. I’m always drawn to
CONTRIBUTORS shooting targets that are recognisable
DQG WKLV LV GHƅQLWHO\ RQH RI WKHP
Paul Abel, Rob Banino, Nisha Beerjeraz-Hoyle, Shaoni @bbcskyatnightmagazine @idadarksky
Bhattacharya, Jamie Carter, Lewis Dartnell, Glenn @skywatcheraustralia @sky_watcher_
Dawes, Dave Eagle, Alastair Gunn, Annie Hogan, RIƅFLDO DVWURSKRWRJUDSK\ DVWUR
Tim Jardine, Pete Lawrence, Scott Levine, Chris QJF QRUWKDPHULFDQHEXOD
Lintott, Mary McIntyre, Jonathan Nicholls, Steve HPLVVLRQQHEXOD F\JQXV FDOGZHOO
Richards, Ian Ridpath, Govert Schilling, Hayley Smith,
Steve Tonkin, Jane Williamson, Penny Wozniakiewicz > orbits is represented, so there are ones put forward are rather bad;
two models for each planet. ‘Andromilky Way’ is the best name.
ADVERTISING SALES Bian Hensley, via email Stuart Buchanan, via email

Advertising Manager Andy Williams Impactful names Could ‘Impactus’ be a name after the
+44 (0)117 300 8803, [email protected] collision? Given it’s a clash of Titans,
Inserts Laurence Robertson +353 (0)87 690 2208 Reading the names put forward for the ‘Perseus’ would have been perfect but
resultant galaxy from the Andromeda that’s taken. William Messer, via email
PRODUCTION and Milky Way merger (Cutting Edge,
‘When galaxies collide’, April 2021), the
Production Director Sarah Powell
Production Coordinator Lauren Morris SOCIETY IN FOCUS
Ad Services Manager Paul Thornton
Ad Coordinator Charles Thurlow Herefordshire month since 2008, but since March 2020
Ad Designer Parvin Sepehr we have held our talks on Zoom due to
Reprographics Tony Hunt, Chris Sutch Astronomical COVID-19. This has, however, allowed us
WR HQJDJH VSHDNHUV IURP IXUWKHU DƅHOG
LICENSING Society was
Over the years we’ve visited a number
Director of Licensing and Syndication established in of astronomical venues including the
Tim Hudson National Space Centre, The Spaceguard
International Partners’ Manager Anna Genevier 2008 and Centre, Norman Lockyer Observatory,
Hanwell Observatory and the Herschel
MARKETING today has Museum of Astronomy.

Head of Circulation Rob Brock about 70 The Society has organised a number of
Head of Marketing Jacky Perales-Morris outreach astronomical events, including
Marketing Executive Kellie Lane Þ Left to right: members. We the 2015 partial solar eclipse with Madley
Press and PR Manager Emma Cooney Environmental Study Centre (MESC) next
Dr Paul Olver (former hold monthly to the BT International Satellite Station,
PUBLISHING & MANAGEMENT which provided a guided tour of its
Herefordshire AS talks, observing facilities. We had clear skies for the eclipse
Managing Director Andrew Davies and over 600 people attended. In July
Group Managing Director Andy Marshall Chairman), Mark nights from 2019 we marked the 50th anniversary of
CEO Tom Bureau Apollo 11, again at Madley, with talks and
Chamberlain (Chairman) autumn to a display of lunar rock samples.
BBC STUDIOS, UK PUBLISHING and Christianne Wakeham
spring and All being well, on 9 September we will
Chair, Editorial Review Boards Nicholas Brett (MESC organiser and return to the Kindle Centre for a talk by
Managing Director, Consumer Products Paul Haley on how observatories
and Licensing Stephen Davies Outreach Speaker) organise trips, developed in the 19th century.
Director, Magazines and Mark Chamberlain, Chairman
Consumer Products Mandy Thwaites visits and local Martin Stratford, Website Manager
Compliance Manager Cameron McEwan > sites.google.com/site/hsastro/home
UK Publishing Coordinator Eva Abramik outreach events. We also host an annual
[email protected]; www.bbcstudios.com
Rev TW Webb lecture in honour of the
EDITORIAL REVIEW BOARD
famous Victorian astronomer who lived
Andrew Cohen, Head, BBC Studios Science Unit;
Deborah Cohen, Editor, BBC Science Radio; and worked in the county.
Steve Crabtree, Executive Producer, BBC Studios;
Dr Erica McAlister; Dr Jessica Wade Herefordshire has some of the darkest

SUBSCRIPTION RATES night skies in the country and we were

Annual subscription rates (inc. P&P): UK cheque/credit card £62.40; Europe & Eire fortunate to be able to use Berrington
Airmail £75; rest of world airmail £85. To order, call 03330 162119 (UK); overseas
+44 (0)1604 973727 +DOO D 1DWLRQDO 7UXVW YHQXH ZKHQ ZH ƅUVW

We abide by IPSO’s rules and regulations. To give feedback established our regular observing nights.
about our magazines, please visit immediate.co.uk,
email [email protected] or We now have two other sites at the
write to The Editor, BBC Sky at Night Magazine,
Immediate Media Co Bristol Ltd, Eagle House, Bristol, BS1 4ST. villages of Fownhope and Bartestree.

Audit Bureau of Circulations Kindle Centre in Hereford City is our
20,788 (combined; Jan–Dec 2020)

© Immediate Media Company Bristol Limited 2021
ISSN 1745-9869

All rights reserved. No part of BBC Sky at Night Magazine may be reproduced in any form
or by means either wholly or in part, without prior written permission of the publisher.
Not to be re-sold, lent or hired out or otherwise disposed of by way of trade at more than
the recommended retail price (subject to VAT in the Republic of Ireland) or in mutilated
condition. Immediate Media Company Bristol Limited is working to ensure that all of its paper
is sourced from well-managed forests. This magazine is printed on Forest Stewardship Council
)6& FHUWLƅHG SDSHU 7KLV PDJD]LQH FDQ EH UHF\FOHG IRU XVH LQ QHZVSDSHUV DQG SDFNDJLQJ
Please remove any gifts, samples or wrapping and dispose of it at your local collection point.

The publisher, editor and authors accept no responsibility in respect of any products,
goods or services that may be advertised or referred to in this issue for any errors,
omissions, mis-statements or mistakes in any such advertisements or references.

main venue for talks. We’ve used it every

20 BBC Sky at Night Magazine September 2021

COVID-19 We pick the best live and virtual astronomy events and resources this month

Odnilsinttaatehknaiicsnnegdmdpsoelonvacetcihneatllsy WHAT’S ON

PICK OF THE MONTH

Live Museum of the Moon Þ Enjoy engaging talks on subjects ranging from stargazing to folklore and cosmology

South West, August–December Online Brecon Beacons Virtual Dark Skies
Luke Jerram’s Museum of the Moon art
installation will be at Bristol Cathedral A brand new night-sky festival comes to mid-Wales, from 24–26 September
until the 30th, after which catch it at
Wells Cathedral (12 October–3 November) Launching online-only this year, we (bottom, left), author of The Greatest
and Bath Abbey (19 November–26 expect big things for this new annual Adventure, exploring the Space Race.
December), accompanied by Moon event for stargazing beginners. /RFDO DVWURQRP\ H[SHUW 0DUWLQ *ULIƅWKV
science, folk concerts, a talk by astronaut will reveal Welsh mythology of the night
Helen Sharman, storytelling, crafts and Astronomer Royal Martin Rees kicks off VN\ DQG WKHUHŝV D FKDQFH WR ƅQG RXW
more. Visit my-moon.org three days of virtual talks and happenings about meteorites and more. Aimed at
that include award-winning physicist Paul anyone (10 and up), events are via Zoom
Online Space debris Davies (top, right) walking us through the and cost £2. Book via bit.ly/3z47yH0.
riddles in our Universe, and Colin Burgess
3 September, 7:30pm
LUKE JERRAM What’s the future for ground-based Follows the society’s AGM. Contact: Cairngorms Astronomy Group takes a
astronomy in a new era of satellite mega- [email protected] look at how aurorae, a frequent local sight
constellations? asks Warwick University’s around the equinoxes, are triggered by
Professor Don Pollacco in this talk from Live Essex stargazing space weather and conditions on the Sun.
the Astronomical Society of Edinburgh. www.cairngormsdarkskypark.org
Visitors are welcome to watch live on the Great Notley Country Park,
ASE’s YouTube channel. bit.ly/3ku3Dza Braintree, 18 September, 6pm Live Astrophotography talk
All ages are welcome to North Essex
Live Stargazing weekend Astronomical Society’s evening, looking Steeton Methodist Church, West Yorkshire,
at the Moon, planets and other objects 23 September, 7:30pm
Otterburn, Northumberland, of interest. Free. northessexastro.co.uk $OO DUH ZHOFRPH WR 'U 3DPHOD :KLWƅHOGŝV
3 and 4 September talk, ‘A Transatlantic Adventure in
Tour the Milky Way, star clusters and Live Cairngorms aurorae Astrophotography’, for Keighley
galaxies from a pub on the edge of the Astronomical Society. £3 on the door.
Northumberland International Dark Glenlivet Public Hall, Ballindalloch, keighleyastronomicalsociety.co.uk
Sky Park. With talks from experienced 26 September, 9pm
astronomer Richard Darn. Suitable for
novices. All equipment provided; £60 per
person, including B&B. bit.ly/3exihlA

Live Knowle meeting

Dorridge Village Hall, Solihull,
6 September, 8pm
Members and visitors are welcome to
Knowle Astronomical Society’s session
on getting the best out of your telescope
and setting it up for astrophotography.

September 2021 BBC Sky at Night Magazine 21



The amateur astronomer’s forum

FIELD OF VIEW

Patchwork project for the RAS bicentennial

Annie Hogan reports on a quilt to mark the Royal Astronomical Society at 200

Annie Hogan is A lot can happen in 200 years, from patchwork squares stitched together in a grid, with ANNIE HOGAN/RAS BICENTENNIAL QUILT PROJECT
a space and the discovery of Neptune and images of an astronomical or geophysical nature.
sewing enthusiast white dwarf stars to detecting
and Membership gravitational waves and The RAS Bicentennial Quilt Project launched in
2IƅFHU DW WKH ‘photographing’ a black hole. The October 2019. Volunteers from a variety of
Royal Astronomical ƅHOG RI DVWURQRP\ KDV FHUWDLQO\ backgrounds – scientists, professional sewers, novice
Society advanced in the two centuries since the Royal crafters, RAS staff and Fellows – gathered together
Astronomical Society (RAS) was founded. The to take part in stitching afternoons. Together, they
Society celebrated its 200th anniversary in 2020 and began to embroider the orbital paths of the planets.
one of the ways chosen to mark this milestone was 7KH ƅUVW IHZ VTXDUHV IRU WKH SDWFKZRUN VLGH RI WKH
by making a commemorative quilt: something quilt began to trickle in. And then the pandemic hit.
tangible that our Fellows and other members could 7KH 5$6 RIƅFHV FORVHG DQG WKH VWLWFKLQJ VHVVLRQV
get involved with; a creative project which the were cancelled. Something that relied upon people
Society could keep for the next one hundred years. huddling around a 2m2 piece of fabric seemed
unthinkable. Until, that is, the advent of virtual
Inspired by Ellen Baker’s 1876 Solar System quilt meetups; the RAS moved its meetings, lectures and
(currently housed at the National Museum of events online, so why not the stitching sessions too?
American History), one side of the bicentennial quilt
features an embroidered depiction of the Solar The in-person sewing sessions had proved popular
System. The other side is made in the tradition of DQG WKH\ GLG VR RQOLQH WRR 'HVSLWH ƅQGLQJ RXUVHOYHV
physically cut-off from one another, these virtual
sessions allowed us to connect across the country,
across continents and across oceans while we
created our own individual squares for the patchwork
side. Like the RAS itself, the bicentennial quilt went
from a small idea conceived by a few individuals to
an international project. We chatted and sewed,
shared ideas and advice, provided encouragement
and inspiration. A little community was born.

Twelve online stitching sessions took place
between April and November 2020 and a total of
100 squares were sent in from all over the globe. Most
excitingly, all of the 20cm x 20cm squares we received
ZLOO EH LQFOXGHG LQ WKH ƅQDO TXLOW 7KH\ DUH PLQLDWXUH
masterpieces in their own right, together forming a
patchwork of nebulae, comets and planets, and also
a collective understanding and appreciation for
astronomy and geophysics. The quilt is a rich tapestry
of experiences and stories that belong to the makers
behind each square. What started as a tribute to the
RAS’s bicentenary has also become a celebration of
people’s enthusiasm, creativity, skill and resilience.

We’ve started the process of sewing the squares
together, but there’s still a lot of work to be done
before the quilt is completed, particularly on the
Solar System side. For more updates about the
project visit www.ras.ac.uk and search ‘quilt’.

September 2021 BBC Sky at Night Magazine 23

Sky at Night
MAGAZINE

SAVE WHEN YOU SUBSCRIBE

TO THE DIGITAL EDITION

Available from

The perfect addition to your stargazing, BBC Sky at Night
Magazine is your practical guide to astronomy, helping you
to discover the night skies, understand the Universe around
us and learn exciting techniques for using your telescope.

Enjoy our Premium App experience now available from

Sky at Night
MAGAZINE

Telescopes that changed

ASTRONOMY
From Galileo’s humble refractor to the
300m-wide radio telescope, Ezzy Pearson
takes a look at the instruments that have
revolutionised the way we see the sky

With rapid technical advances, Over 400 years ago in 1608, Dutch optician
telescopes are becoming ever +DQV /LSSHUVKH\ ƅOHG D SDWHQW IRU KLV
more available for everyone to QHZ LQYHQWLRQ WKH UHIUDFWLQJ WHOHVFRSH
enjoy the wonders of the night sky $VWURQRP\ ZRXOG QHYHU EH WKH VDPH
DJDLQ ,Q WKH FHQWXULHV VLQFH WHOHVFRSHV
KDYH KHOSHG XV JOLPSVH WKH IDUWKHVW
UHDFKHV RI WKH 8QLYHUVH DQG EHJLQ WR XQSLFN LWV VHFUHWV

)URP WKH SHUVRQDO WHOHVFRSHV *DOLOHR DQG 1HZWRQ NHSW
LQ WKHLU REVHUYDWRULHV WR WKH FRORVVDO WHOHVFRSHV WKDW KDYH
WR EH EXLOW LQWR WKH VLGHV RI PRXQWDLQV ZH WDNH D ORRN DW
WKH LQVWUXPHQWV WKDW KDYH PDGH Ś RU KRSH WR PDNH Ś WKH
ELJJHVW LPSDFWV LQ WKH ƅHOG RI DVWURQRP\ť

GALILEO’S TELESCOPE Z Two of Galileo’s
early ‘optik tubes’
The Italian astronomer was the first with tiny lenses:
to systematically map the heavens they were about
1.5 inches across
In May 1609, Galileo Galilei learned of a remarkable
new invention from the Netherlands that used lenses
to make distant objects look as if they were nearby.
6XFK D GHYLFH FRXOG ƅQDOO\ EULQJ WKH KHDYHQV KH
VWXGLHG LQWR YLHZ VR KH VHW DERXW FUHDWLQJ KLV RZQ
YHUVLRQV DQG LQFUHDVHG WKH PDJQLƅFDWLRQ XS WR [

2QH RI *DOLOHRŝV ƅUVW WDUJHWV ZDV WKH 0RRQ DQG
KLV WHOHVFRSH UHYHDOHG WKH FUDWHUV DQG PRXQWDLQV RQ
LWV JUH\ VXUIDFH +H DOVR REVHUYHG WKH QH[W EULJKWHVW
REMHFW LQ WKH QLJKW VN\ -XSLWHU 2Q -DQXDU\
KH QRWLFHG LW ZDV MRLQHG E\ şWKUHH ƅ[HG VWDUV WRWDOO\
LQYLVLEOH E\ WKHLU VPDOOQHVVŠ WKDW VHHPHG WR DOLJQ
SHUIHFWO\ ZLWK WKH SODQHW 2YHU WKH QH[W IHZ QLJKWV
KH IRXQG WKH\ ZHUHQŝW ƅ[HG DW DOO EXW PRYHG ZLWK
-XSLWHU 2Q -DQXDU\ KH QRWLFHG D IRXUWK 7KHVH
ZHUHQŝW VWDUV EXW PRRQV RUELWLQJ WKH SODQHW

%\ 0DUFK *DOLOHR KDG SXEOLVKHG KLV ƅQGLQJV LQ
his seminal book, Sidereus Nuncius ,W SURYLGHG
FRPSHOOLQJ HYLGHQFH WKDW &RSHUQLFXV ZDV ULJKW LQ KLV
theory that the Sun, not Earth, was at the centre of
WKH 8QLYHUVH DQG WKDW WKH WHOHVFRSH ZRXOG EH WKH
PRVW SRZHUIXO WRRO \HW IRU H[SORULQJ WKH FRVPRV

> A replica of Y NEWTON’S TELESCOPE ADVENTURE_PHOTO/ISTOCK/GETTY IMAGES, GIANNI TORTOLI/SCIENCE PHOTO LIBRARY,
WORLD HISTORY ARCHIVE/ALAMY STOCK PHOTO
Newton’s telescope. The design that formed the foundation
His spherical of every modern reflector
primary mirror
tackled the issue %\ WKH PLG WK FHQWXU\ D FRPPRQ ODPHQW ZDV KHDUG
of chromatic DPRQJ DVWURQRPHUV ZK\ ZHUH WKHUH FRORXUHG EDQGV
aberration DW WKH HGJH RI WKHLU WHOHVFRSHŝV YLHZ" ,W ZDV 6LU
Isaac Newton who realised this effect, known
as chromatic aberration, was created by the
HGJH RI WKH OHQV LQ WKH WHOHVFRSH DFWLQJ OLNH
D SULVP DQG VSOLWWLQJ WKH ZKLWH OLJKW RI VWDUV
into several colours.
6HYHUDO WHOHVFRSH PDNHUV ZHUH DWWHPSWLQJ
WR ƅ[ WKH SUREOHP E\ XVLQJ PLUURUV LQVWHDG RI

OHQVHV WR IRFXV OLJKW 7KH WKHRU\ ZDV VRXQG EXW ZDV
SURYLQJ GLIƅFXOW WR SXW LQWR SUDFWLFH ,GHDOO\ \RXŝG QHHG
D SDUDEROLF PLUURU EXW WKHVH ZHUH KDUG WR SURGXFH E\ KDQG
1HZWRQ XVHG D VSKHULFDO PLUURU ZKLFK ZDV HDVLHU WR JULQG 7KLV
VROYHG WKH FKURPDWLF DEHUUDWLRQ EXW LQWURGXFHG DQRWKHU RSWLFDO
GHIHFW VSKHULFDO DEHUUDWLRQ ZKHUH WKH LPDJH GRHVQŝW IRFXV
XQLIRUPO\ 1HZWRQ DOVR XVHG D VHFRQGDU\ PLUURU VR WKH LPDJH
FRXOG EH YLHZHG PRUH HDVLO\ IURP WKH VLGH RI WKH WHOHVFRSH
1HZWRQ VKRZHG KLV WHOHVFRSH DW WKH 5R\DO 6RFLHW\ RI /RQGRQ
LQ DQG LW ZDV VXFK D KLW WKDW KH ZDV DVNHG WR GHPRQVWUDWH
LW WR .LQJ &KDUOHV ,, )LIW\ \HDUV ODWHU LQ DQRWKHU DVWURQRPHU
-RKQ +DGOH\ ZRUNHG RXW KRZ WR FUHDWH SDUDEROLF PLUURUV
HOLPLQDWLQJ WKH VSKHULFDO DEHUUDWLRQ 7RGD\ WKH 1HZWRQLDQ
GHVLJQ LV WKH IRXQGDWLRQ RI DOPRVW HYHU\ UHƆHFWLQJ WHOHVFRSH
available on the market. >

September 2021 BBC Sky at Night Magazine 27

HUBBLE One of Hubble’s most
iconic images has been
SPACE TELESCOPE captured twice: this is the
25th anniversary image
Above the atmosphere, Hubble could get of the ‘Pillars of Creation’,
an uninterrupted view of the cosmos
taken in 2014
Astronomers have long dreamed of putting a telescope in
space. Above the clouds and able to point away from the
Sun, such a telescope could observe 24 hours a day without
atmospheric disturbance or light pollution. But it would take
until 1990 – and the work of both NASA and the European
Space Agency (ESA) – to make the dream a reality. On
$SULO WKDW \HDU WKH ƅUVW HYHU YLVXDO VSDFH WHOHVFRSH
Hubble, launched into orbit.

But the joy of launch was short-lived when it became
DSSDUHQW WKDW WKH P ZLGH PLUURU ZDV WRR ƆDW 7KH HUURU ZDV
around 1/50th the thickness of a human hair, but it stopped
the mirror focusing properly and its images were blurred.
Fortunately, Hubble was made to be upgraded. In December
D VHUYLFH PLVVLRQ LQVWDOOHG D QHZ LQVWUXPHQW WR ƅ[ WKH
problem, bringing the Universe sharply into focus.

Over the last 30 years, Hubble has revolutionised our view of
the cosmos, imaging everything from neighbouring planets to
GLVWDQW JDOD[LHV ,WV GDWD KDV EHHQ XVHG LQ RYHU VFLHQFH
papers while its images have become part of popular culture.
Recently, it was feared that Hubble’s days might soon be over.
In June 2021, a computer fault shut down the telescope, but
RSHUDWRUV KDYH UH HVWDEOLVKHG FRQWDFW DQG ƅ[HG WKH SUREOHP
It now looks like the reign of Hubble is set to continue.

$V WKH ZRUOGŝV ƅUVW VSDFH
telescope, Hubble was
launched in 1990 with
an initial price tag of $1.5bn

28 BBC Sky at Night Magazine September 2021

SOHO Z SOHO allows
astronomers to
For 25 years, the SOHO spacecraft make more accurate
has kept a close watch over the Sun predictions about

While most telescopes are pointed away from solar events,
the Sun, the Solar and Heliospheric Observatory including storms
(SOHO) has spent the last 25 years looking at it.
The spacecraft, a joint mission of ESA and NASA, ILLUSTRATION
was meant to study the Sun for just two years,
investigating its expansive outer atmosphere, surface
and internal structure. This meant astronomers could
predict solar storms, which can harm astronauts and
damage space hardware, a week earlier than before.
It launched in 1995, but has proved so useful that its
mission has been extended multiple times.

For over two decades, SOHO has provided a
near real-time view of the solar surface, allowing
astronomers to predict solar storms earlier than they
could before. Its watch has extended through two of
the Sun’s 11 year-long solar cycles, giving insights that
enable astronomers to accurately forecast space
weather trends over decades rather than days.

Artists’ impressions Y EXTREMELY
of the E-ELT in Chile LARGE TELESCOPES
and (below) the
TMT in Hawaii…

ILLUSTRATION Technological advances enable the
construction of truly enormous scopes
…showing the hexagonal NASA/ESA AND THE HUBBLE HERITAGE TEAM (STSCI/AURA), NASA, ESA/ATG
sectioning technique When it comes to astronomical telescopes, bigger is MEDIALAB/ESA/NASA SOHO, ESO, TMT INTERNATIONAL OBSERVATORY
that will be used better. A larger dish gathers more light and increases
to construct the resolution, making detail sharper. For telescopes
the mirrors on Earth, however, once mirrors get beyond a few
metres wide, atmospheric seeing – where the shifting
ILLUSTRATION atmosphere distorts incoming light – blurs the image.
This makes building anything larger pointless.

Until 1990, that is, when the European Southern
Observatory (ESO) pioneered a new technology
called adaptive optics, which subtly deforms the
shape of the mirror to correct for the effects of
seeing. Now the only limitation was how big you
could make your mirror, leading to a new generation
of telescopes dubbed Extremely Large Telescopes
(ELTs) that will look deeper and with more precision
than anything that has gone before.

There are two ELTs currently in construction. The
Thirty Meter Telescope (TMT) will have a 30m-wide
mirror and is being built on Hawaii’s Mauna Kea, with
DQ H[SHFWHG ƅUVW OLJKW LQ (OVHZKHUH WKH P
wide European Extremely Large Telescope (E-ELT)
is being built in Chile, ready to start observing in 2025.

Building such large mirrors is a challenge: both
mirrors are being split up into dozens of hexagonal
sections that will be placed together in a honeycomb
to create one giant mirror surface. >

September 2021 BBC Sky at Night Magazine 29

ARECIBO

TELESCOPE Z

The huge radio dish opened up
the radio Universe

Built into a sinkhole in Puerto Rico, the create radar maps of Mars ahead of In 1974, the Arecibo Telescope was
305m-wide Arecibo telescope reigned as the Viking lander missions, as well as used to send an interstellar radio
the largest radio telescope in the world for glimpsing beneath the clouds of Venus
over half a century. And yet when it was DQG ƅQGLQJ LFH RQ 0HUFXU\ message to see if aliens might respond
ƅUVW SXW WR XVH LQ LWV SULPDU\ SXUSRVH
ZDVQŝW VFLHQWLƅF EXW PLOLWDU\ Ś GHWHFWLQJ /RRNLQJ IXUWKHU DƅHOG $UHFLER KDV they aren’t caused by one-off cataclysmic
PLVVLOHV ERXQG IRU WKH 86 ,Q KRZHYHU detected the faint signals from distant events, such as stellar collisions.
it was transferred to the National Science radio sources and was key in studying
)RXQGDWLRQ EHFRPLQJ D VFLHQWLƅF IDFLOLW\ SXOVDUV ,Q LW GHWHFWHG WKH ƅUVW 7KH WHOHVFRSH ODVWHG \HDUV EXW LQ
repeating fast radio burst, proving that August and November 2020, two of its
7KH ƅUVW FKDQJH PDGH ZDV WKH support cables snapped, damaging the
installation of S-Band radar equipment, dish. It was due to be decommissioned,
which could observe Solar System objects but on 1 December a third-cable breakage
as far out as Saturn. This was used to caused a support tower to collapse,
completely destroying the telescope.

JAMES WEBB SPACE TELESCOPE V

Peering through cosmic dust, JWST will expose how stars and galaxies grow

,Q +XEEOHŝV JORULRXV LPDJHV KDG EHHQ PDNLQJ The mighty James
headlines for several years and NASA, keen to follow Webb Space Telescope
up on its success, began working on what’s now will capture the glow
known as the James Webb Space Telescope (JWST). IURP WKH ƅUVW VWDUV WR
shine in the Universe
The JWST’s main science goals are to look at how
galaxies, stars and planets have grown from the
earliest eras of the Universe to today. To do this, it
will look at infrared radiation, which can pass through
the dust in space that obscures visible light, allowing
it to peer into the stellar nurseries and the cores of
active galaxies. The radiation also allows it to see
objects, such as planets, which are too cool to glow
in the visible spectrum.

+RZHYHU DV WKH WHOHVFRSHŝV RZQ KHDW ZLOO SURGXFH
infrared energy, JWST is being kept shaded from the
Sun’s heat with a huge sunshield. This has proved to
be the telescope’s most troublesome component.
7KH VKLHOG LV PDGH RI ƅYH OD\HUV RI GHOLFDWH IRLO HDFK
the size of a tennis court, one of which tore in 2018
causing the entire mission launch to be pushed back.

After 25 years of planning, building and delays,
WKH -:67 LV ƅQDOO\ UHDG\ WR ODXQFK (DUOLHU WKLV \HDU
ERWK WKH VXQVKLHOG DQG WKH P PLUURU ZHUH IROGHG
XS VR WKDW WKH\ FRXOG ƅW RQ ERDUG DQ $ULDQQH
ODXQFK URFNHW UHDG\ Ś KRSHIXOO\ Ś WR KHDG WR RUELW LQ
November this year.
PHOTOSPIRIT/ALAMY STOCK PHOTO, ADRIANA MANRIQUE GUTIERREZ/NASA
ANIMATOR, EVERETT COLLECTION INC/ALAMY STOCK PHOTO

ILLUSTRATION
Dr Ezzy Pearson is BBC Sky
at Night Magazine’s news
editor. She has a PhD in
extragalactic astronomy

30 BBC Sky at Night Magazine September 2021

Stargazing for everyone

In the 1960s and ’70s, two new types of telescope helped to bring the
heavens to more people than ever before

Þ A vintage Celestron C8 from the 1970s Þ ...and Celestron founder Tom Johnson ,Q &HOHVWURQ FUHDWHG ZKDW ZRXOG
EHFRPH LWV ƆDJVKLS WHOHVFRSH WKH &
with its trademark orange tube... with a 14-inch version of his SCT line The 8-inch telescope hit a sweet spot
Ś LW ZDV ODUJH HQRXJK WR YLHZ GHHS VN\
In the early days of astronomy, any Just like Sir Isaac Newton, he was using objects, but not so big as to be unwieldy
budding stargazer had one huge hurdle easy-to-craft spherical mirrors, but using and expensive. With its distinctive orange
to overcome: getting a telescope. For a Schmidt corrector plate to remove barrel it was a huge success.
centuries, the only way to acquire one was the spherical aberrations. Invented by
to either buy an expensive, hand-made Bernhard Schmidt in 1930, this was a glass Yet the C8 still came with a fairly hefty
model from a master telescope maker, or plate positioned across the opening of the SULFH WDJ DSSUR[LPDWHO\ RU
spend hours laboriously grinding lenses telescope tube, adjusting the incoming £5,050, in today’s money) that was beyond
or mirrors to make your own. It was the light so that it focused properly, even on a the range of many would-be astronomers.
latter approach Tom Johnson took when spherical mirror. Johnson found a way to
he introduced his sons to stargazing in mass-produce these plates. By the early Thankfully for the more budget-
America in the late 1950s. V KH KDG KLV RZQ WHOHVFRSH FRPSDQ\ conscious, another astronomer, John
&HOHVWURQ SDUW RI 9DORU (OHFWURQLFV DQG Dobson, had been working on making it
As he worked on the project, Johnson began creating high-quality, yet affordable, HDVLHU WR EXLOG \RXU RZQ WHOHVFRSH +LV
became more and more convinced there telescopes for the mass market. design reduced the instrument down to its
was an easier way to make telescopes. PRVW EDVLF HOHPHQWV Ś WKH RSWLFV D WUXVV
to hold them and a simple swing mount
like those used on cannons for centuries.
Dobson used affordable porthole glass
along with other cheap materials to
create large amateur telescopes, which,
while not offering as high-quality views
as commercially built telescopes, cost
D IUDFWLRQ RI WKH SULFH +H HQFRXUDJHG
people around the world to copy his
design and today ‘Dobsonian’ telescopes
are a common sight at any star party.

The C8 and the Dobsonian helped to
bring the stars within reach of the masses.

John Dobson with
one of his homemade
‘Dobsonian’ telescopes

Þ Celestron’s most advanced 8-inch

system is currently the CGEM II 800
EdgeHD (right); while Dobsonian
telescopes have also come of age with
computerised models like the Skyliner-
200P Flextube SYNSCAN Go-To (left)

September 2021 BBC Sky at Night Magazine 31

The fundamentals of astronomy for beginners

EXPLAINER EXTRA

Here comes the dark-sky season!

With darker skies upon us, Scott Levine takes a month-by-month tour of the
must-see sights for the longer nights around the corner

The start of autumn in the Northern CYGNUS
Hemisphere is just a matter of weeks
away, but we can already see the Summer Deneb
nights getting longer, with sunsets Triangle
now over an hour and a half earlier
than they were around the June Altair
solstice. As these earlier nights for observing come
along, let’s look at the exciting sights we can look AQUILA Vega
forward to seeing as the dark-sky season begins.
LYRA
September
Plough
With September here, the long summery days are
gradually changing into early nights. Indeed, we’ll BOÖTES URSA
see spring and summer’s stars making way for the MAJOR
dark-sky season as autumn approaches. Arcturus

Let’s begin our dark-sky adventure at a well-known Þ In September, the Plough connects to Arcturus and the Summer Triangle...
asterism, the Plough, sitting upright just above the
northern horizon. The next bright star to its south- CASSIOPEIA PEGASUS
southeast is Arcturus (Alpha (α) Boötis), which we
usually think of as a springtime star. W M15
Double Cluster
1H[W KLJK RYHUKHDG ZH ƅQG WKH Summer AQUARIUS
Triangle’s stars: Vega (Alpha (α) Lyrae), Altair (Alpha M31
(α) Aquilae) and Deneb (Alpha (α) Cygni), and then
drop towards the east for the Great Square of M34 Great Square Jupiter
Pegasus. Maybe we can spot Capella (Alpha of Pegasus
(α) Aurigae), just above the northern horizon. ANDROMEDA CAPRICORNUS
Water
CHARTS: PETE LAWRENCE With binoculars, let’s look for the Andromeda Circlet Jar
Galaxy, M31, just to the northeast of Pegasus, the Neptune
Winged Horse, and then the Double Cluster in PERSEUS M33
Perseus, the Hero a bit further northeast.
PISCES
Meanwhile, the Moon catches up with Jupiter
and Saturn on 17 September. With good telescopes, Þ ťDQG ZH FDQ XVH WKH *UHDW 6TXDUH RI 3HJDVXV WR ƅQG WKH $QGURPHGD *DOD[\ 0
we may be able to see deep, blue Neptune to their
east. The planet reaches opposition on the 14th.

October

With the autumn equinox (22 September) behind us,
WKHUHŝV PRUH QLJKW WKDQ GD\ QRZ IRU WKH ƅUVW WLPH
since March, and it’ll stay that way until March 2022.

Fomalhaut (Alpha (α) Piscis Austrini) is almost
due south at mid-evening. It’s the southernmost
ƅUVW PDJQLWXGH VWDU ZH FDQ VHH LQ WKH 1RUWKHUQ
Hemisphere, in a part of the sky without many

32 BBC Sky at Night Magazine September 2021

CETUS AQUARIUS

Jupiter CAPRICORNUS

Diphda Saturn
(Deneb Kaitos)

Fomalhaut PISCIS
AUSTRINUS
S
October’s starry SSW
delights include
Fomalhaut
and Diphda

other bright stars. With so little happening nearby, Capella Uranus
it appears as a slightly oddball light a few degrees
above the horizon. Diphda (Beta (β) Ceti), also known AURIGA Pleiades
as Deneb Kaitos, is about 25° east of Fomalhaut. Winter
Hyades
The waxing gibbous Moon meets up with Jupiter
and Saturn on the 14th, about 25° to Fomalhaut’s Aldebaran
west. Through binoculars, we can see the shadows
reaching across the Moon’s face as lunar dawn Castor GEMINI TAURUS
breaks along its mid-section. Pollux
ORION
On the 23rd, the Moon glides between the Hyades
and the Pleiades star clusters, and starts moving Betelgeuse
across the Winter Hexagon. Venus reaches greatest
elongation, about 46° east of the Sun, on the 29th. M44 Rigel

Back in the north, the starry constellation of Procyon LEPUS
Cassiopeia, the Queen is high overhead with
Cepheus, the King to its west, Perseus, the Hero to CANIS
its east and the Milky Way running through them all. MINOR

November Sirius CANIS MAJOR

Deeper into autumn, the Plough is low above the E ESE SE SSE
northern horizon. Arcturus has departed now, but
let’s follow the line between Megrez (Delta (δ) Ursae Þ November +5.7 is on the verge of naked-eye visibility, when it’s at
Majoris) and Dubhe (Alpha (α) Ursae Majoris), across opposition on the 4th.
the top of the blade to Capella, whose golden colour offers the perfect
is stunning on these stark nights. opportunity to December
explore the stars
Widening our gaze, we can see most of the in the Winter The start of winter is just three weeks away now, at
Winter Hexagon: the asterism of six of the sky’s Hexagon, including the winter solstice on the 21st, so these are the year’s
brightest stars, one each in six constellations, Aldebaran, a longest nights. With sunset before 16:00 UT these
covering a patch of sky so enormous that the Moon useful marker are my favourite nights for observing in the year.
needs four nights to cross it. Anti-clockwise around for the Hyades Indeed, let’s spend a little extra time simply soaking
it are Capella, then Pollux (Beta (β) Geminorum), and the Pleiades in that extra darkness without any worry about which
Procyon (Alpha (α) Canis Minoris), Sirius (Alpha (α) star clusters star is which.
Canis Majoris), Rigel (Beta (β) Orionis), and Aldebaran
(Alpha (α) Tauri). This is also the start of Orion season! All of the
Hunter’s seven famous stars are above the southern
Aldebaran marks the southeast end of the southern horizon by mid-evening, but can you remember their
arm of the V-shaped Hyades, with the tiny, dipper- names? The red supergiant Betelgeuse (Alpha (α)
shaped Pleiades a short hop away. They’re among Orionis), and Bellatrix (Gamma (γ) Orionis) are his
the closest star clusters to us, about 150 and 450 shoulders. Saiph (Kappa (κ) Orionis), and icy blue
lightyears away respectively. They’re truly stunning in Rigel are his feet. The belt stars are Alnitak (Zeta
binoculars and worth observing for a good, long time. (ζ) Orionis), Alnilam (Epsilon (ε) Orionis), and Mintaka
Aldebaran isn’t part of the cluster, but it sits about (Delta (δ) Orionis). Let’s visit them as they rise a little
halfway between the Hyades and Earth. The (almost, earlier each night and make their way a little further
WR ƅUVW TXDUWHU Moon passes through on the 10th and to the west at the same time each night.
11th, and the full Moon splits the clusters on the 19th.
Many of us also know the Orion Nebula; the star- >
When it comes to the planets, we can also catch
Jupiter and Saturn in the early evening, and a pair of
binoculars will help you spot Uranus, which at mag.

September 2021 BBC Sky at Night Magazine 33

NGC 1977

Caldwell 69 M43 M42

Meissa h e e
q q
Trapezium
cluster

Betelgeuse _ Bellatrix

ORION a f NGC 1980

t S

Þ A small telescope will show you the Trapezium

Cluster in the middle of Orion’s Sword...

M78 Alnilam b ORION Caldwell 69

Alnitakc ¡ Mintaka h Meissa

NGC 2024 Collinder 70

d

IC 434/
B33

e M42 q
f
q
NGC 2232 Rigel
S
`
Þ … and you’ll see a ladder of three stars extending
Saiph g
from the star Meissa within Orion’s head

> forming region in the middle of his sword, with the Þ December is Mirfak (Alpha (α) Persei) and the Alpha Persei
Trapezium Cluster deep within it. Let’s look at his Cluster, about 20° to the west of Capella, are also
head too; Meissa (Lambda (λ) Orionis) is the brightest the time to get to an amazing sight through binoculars.
star in the Caldwell 69 open cluster. With binoculars, know the sights in
we can see a dusty glow there, as well as a beautiful Orion, the Hunter The year 2022 starts with Jupiter and Saturn
ladder of three stars extending from Meissa. Orion’s lingering in the last of the glowing twilight, with
Belt is also part of a glowing cluster, Collinder 70, þ See in the New the crescent Moon racing through on 5 January.
with the Horsehead and Flame Nebulae nearby We might also be able to catch Mercury alongside
%DUQDUG DQG 1*& 7KH ƅUVW RI WKHVH WDUJHWV Year with Capella Saturn for a couple of nights centred on the 10th, and
is a challenge, needing a large scope and dark skies. and enjoy the Venus is hiding there too. This could all be tough to
treasures of Auriga, see, however, so be patient.
Meanwhile, the Moon is a waxing crescent when it including clusters
joins the gas giants on 8 December, and it’s full when M36, M37 and M38 _ Capella
it arcs above Betelgeuse on the 19th.

January ` ¡
Menkalinan Almaaz
Happy New Year! Having passed the winter solstice
on 21 December, the nights are slowly shortening. Collinder 62 dc

We’re six months from summer now. If you can Kids
believe it, the Summer Triangle is still with us. It’s
spent that time crossing high overhead, and now h
its stars call to us through the wintry western dusk.
AURIGA o NGC 1857 +
The constellation of Auriga, the Charioteer is
high towards the south in January. Its brightest star e i ‘The Cousins’
Capella has the nickname ‘The Goat Star’, so let’s
look for the pair of stars called The Kids, about 5° m NGC 1778
WR LWV VRXWK $ERXW p ZHVW RI &DSHOOD ZHŝOO ƅQG
Menkalinan (Beta (β) Aurigae), with another, almost- Starfish
matching pair, which I call ‘The Cousins’, about 5° p Cluster, M38
to its south. The balance and symmetry of these is Cheshire
something I look forward to all winter. Cat Hassaleh

With binoculars, we can scan the distant star f
clusters scattered through the constellation,
including the Pinwheel, Salt and Pepper and 6WDUƅVK Pinwheel NGC 1893
Clusters (M36, M37 and M38). Let’s also see if we can Cluster, M36
spot some small star chains sprinkled among them.
Salt and Pepper r
Cluster, M37
CHARTS: PETE LAWRENCE
Elnath TAURUS
`

34 BBC Sky at Night Magazine September 2021

Dark-sky season challenges

Expand on your observing targets each month, whether it’s with meteor showers (naked eye),
deep-sky objects (binoculars) or planets (telescopes). Here are some suggestions:

SEPTEMBER Try and spot Neptune with a telescope when it’s

at opposition –in the opposite position on the sky to the Sun
– on 14 September.

OCTOBER The peak of the Orionid meteor shower takes place

on the night of the 21/22 October. With the Moon out of the way
and an expected ZHR (zenithal hourly rate) of 20, it should be
favourable for naked-eye observing.

NOVEMBER With binoculars look for the Hyades open cluster

in Taurus, the Bull, Also this month, Uranus is at opposition
on the 4th.

DECEMBER The Geminid meteor shower peak takes place on

13/14 December with a ZHR of 120.

JANUARY Use binoculars to search for the open clusters M36, A meteor shower peak, like the Geminids
(on 13/14 December) is a wonderful
M37 and M38 in the constellation of Auriga, the Charioteer. opportunity for astrophotography

FEBRUARY This is a good time for getting wide-field views of

the Beehive Cluster in the constellation of Cancer, the Crab.

CANCER Castor that Arcturus has sneaked back into the night. Its
Pollux welcoming red glow is a sign that even though we
Sickle feel the nights shrinking, spring is on its way.

LEO M44 GEMINI Betelgeuse culminates at 21:00 UT early in the
month. With Orion standing tall above the horizon,
Regulus Acubens it’s a great moment to rewind our minds and
remember a few months ago. Back then, those stars
M67 Altarf CANIS were just climbing into the eastern sky as the last of
MINOR the leaves fell to our feet. Before long, Orion will fall
HYDRA into the dusk as new buds pop onto the trees.
Procyon
If we search through the dim constellation of
Þ In February February Cancer, the Crab, in the patch of sky between
Gemini, the Twins and Leo, the Lion’s ‘Sickle’, we’ll
try and spot the We’ve come to the last full month of the dark-sky ƅQG WKH Beehive Cluster’s thousand stars.
densely populated season. The Sun sets an hour later at the start of the
Beehive Cluster, month than it did at December’s solstice, and we’ll Mornings are the best time for spotting planets this
M44, within the dim see another additional hour of daylight by the end month. Venus, as it so often does, will stop us in our
constellation of of the month. tracks, glowing just before sunrise. On 5 February, we
Cancer, the Crab might be able to spot it with Mars and Mercury low
All of Canis Major, the Great Dog is above the above the eastern horizon. The Moon slides through
southern horizon by mid-evening now. The ‘Dog the Winter Hexagon again from the 9th to the 13th,
Star’, Sirius (Alpha (α) Canis Majoris), culminates and then waves at Venus as a waning crescent on
– appears at its highest position, due south – at the 27th. With that, the spring equinox is only three
21:00 UT by mid-month. Around this time we’ll notice weeks away on 20 March.

There’s more than enough to keep any astronomer
busy all the way through the dark-sky season until
next spring, so let’s get started right away and take
a look tonight!

Scott Levine is a naked-eye observer
and an astronomy writer based in
New York’s Hudson Valley

September 2021 BBC Sky at Night Magazine 35

ESA/NASA, BILL INGALLS/NASA/HANDOUT, GCTC,
DPA PICTURE ALLIANCE/ALAMY STOCK PHOTO,
MATT HEINTZE/CALTECH/MIT/LIGO LAB

SSoPyouACwant toE?work in

36 BBC Sky at Night Magazine September 2021

The space industry has a wide range
of job opportunities, from becoming an
astronaut to being a member of Mission
Control. You could be part of the team
training astronauts to go into space or
build devices to search for gravitational
waves – the options are almost endless

The space sector is
thriving. Hayley Smith
of the National Space
Academy reveals how
GCSE and A-Level
students can prepare
for their dream job

A stronauts and astronomers are
XVXDOO\ WKH ƅUVW MREV WKDW VSULQJ
WR PLQG ZKHQ \RX WKLQN RI VSDFH
FDUHHUV EXW KDYH \RX HYHU KHDUG RI
D VSDFH ODZ\HU DQ DVWUR HFRORJLVW
RU D VSDFH PDUNHWLQJ H[HFXWLYH"
6SDFH RIIHUV D ZLGHU UDQJH RI FDUHHU RSSRUWXQLWLHV
WKDQ \RX PD\ WKLQN LQ HQJLQHHULQJ EXVLQHVV ZHE
GHYHORSPHQW ZULWLQJ DFFRXQWDQF\ DUW VFLHQWLƅF
UHVHDUFK GDWD DQDO\VLV FRPSXWLQJ DQG PHGLFLQH

7KH 8. VSDFH LQGXVWU\ LV JURZLQJ WRR ,W KDV D
WRWDO DQQXDO LQFRPH RI d EQ DQG HPSOR\V RYHU
SHRSOH 3OXV WKHUH DUH VHYHQ QHZ VSDFHSRUWV
SODQQHG WR EH RSHUDWLRQDO LQ WKH 8. ZLWKLQ WKH QH[W
VL[ \HDUV 7KH 8. LV DOVR D PHPEHU RI WKH (XURSHDQ
6SDFH $JHQF\ (6$ ZKLFK WUDLQV DVWURQDXWV DQG
ODXQFKHV PLVVLRQV WR H[SORUH WKH 6RODU 6\VWHP
DQG EH\RQG 7KHUH DUH PDQ\ URXWHV LQWR WKH VSDFH
VHFWRU DQG ZKLFK RQH \RX WDNH GHSHQGV RQ \RXU
XQLTXH EOHQG RI VNLOOV DQG LQWHUHVWV >

Astronauts in training
have entire teams behind

them, even underwater!

$ TXDOLƅFDWLRQ LQ D VFLHQFH EDVHG
subject can be a good launchpad
for a career in the space industry

Producing
illustrations of
the cosmos is an
opportunity for
budding artists

to join the
space industry

ILLUSTRATION

> Consider a mission like the James Webb Space Think about what you love doing. You’re more Þ The National
Telescope. Engineers design, build and maintain the likely to do well at the things you’re passionate about
spacecraft. Computer programmers write code so the and you’ll be happier in your work too. Technical Space Academy
spacecraft can perform tasks and communicate with FDUHHUV VXFK DV HQJLQHHULQJ QHHG D JRRG VFLHQWLƅF holds regular career
Mission Control. Flight controllers make everything background, so sciences and maths at A-Level will events for students
run smoothly. Lawyers ensure legislation is in place keep your options open. Career events like those run
for the launch. Astrophysicists analyse data and by the National Space Academy are a great way
artists illustrate cosmic phenomena, while writers WR H[SHULHQFH WKH UDQJH RI MREV DYDLODEOH DQG PHHW
FRPPXQLFDWH VFLHQWLƅF GLVFRYHULHV WR WKH ZRUOG people from the industry.

A mission to the International Space Station (ISS) 3HUKDSV \RX DOUHDG\ NQRZ ZKDW MRE \RX ZDQW
needs astronauts like Tim Peake to travel into space, WR GR 8VH WKH MRE DV D VWDUWLQJ SRLQW DQG ZRUN
maintain the station and perform experiments. backwards from it to see what routes will help you
A large ground team makes these missions happen, get it. Research your chosen career to make sure it’s
training astronauts, ensuring operations run smoothly right for you. Often, we only see the most exciting or
and planning the astronauts’ schedules. ISS systems JODPRURXV SDUWV RI D MRE $VWURSK\VLFLVWV GRQŝW VSHQG
are designed, developed and maintained by scientists their time on top of a mountain gazing through a
and engineers. While medics study the effects telescope; usually they can be found at a computer
of microgravity on the human body, doctors and
NASA, NASA/ESA/AND G. BACON (STSCI), JOHN BIRDSALL/ALAMY SV\FKRORJLVWV ƅQG ZD\V WR RYHUFRPH WKH EDUULHUV WR EMPLOYEE PROFILE
STOCK PHOTO, NATIONAL SPACE ACADEMY, ESA KXPDQ VSDFHƆLJKW VR ZH PLJKW RQH GD\ VHH KXPDQ
footsteps on Mars. Libby Jackson • Job title: Human Exploration
Programme Manager, UK Space Agency
Deciding on a career path
Libby looks after the UK’s interests in the human
So how do you know which career path you should VSDFHƆLJKW SURJUDPPH
choose? The good news is that you don’t need to
decide right away. If you’re selecting options for “Imagine hopping from one lily pad to another, over
your GCSEs or A-levels, or thinking further ahead a pond. It’s a bit misty, but don’t lose sight of the other
to what you might want to do after leaving school, side. Do what you enjoy and don’t listen to anyone who tells you that you
remember that the diversity of careers in the space shouldn’t be doing it because of what you look like or who you are or
industry means you don’t necessarily need to choose where you’re from. If you’re enjoying it, do it.”
D VSHFLƅF VHW RI VXEMHFWV

38 BBC Sky at Night Magazine September 2021

EMPLOYEE PROFILE

Dr Natasha Stephen • Job title:
Director of Plymouth Electron
Microscopy Centre

Natasha combined her love of
JHRORJ\ DQG VSDFH WR EHFRPH
D SODQHWDU\ JHRORJLVW

“There are lots of opportunities within the space
industry, even at an early age. Speaking to
people about them is a great way to start. Formal
organisations, such as UKSEDS (for students) or
the UK Planetary Forum, can help too. Many
space engineering companies and science
groups offer placements and work experience.”

good at a wide range of activities,” says Lucy van der
Tas, Head of Talent Acquisition at ESA. “Astronauts
QHHG WR EH SK\VLFDOO\ ƅW KDYH JRRG PRWRU
coordination and be comfortable with underwater
training, which simulates microgravity.

“Our astronauts must be team players and get
along with others. That’s critical if you’re going to
VSHQG PRQWKV LQ FORVH FRQƅQHPHQW 7KH\ KDYH
to stay calm under pressure, so they take the
right steps in an emergency. They also need good
communication skills and patience, as it can take
WLPH WR JHW DVVLJQHG WR WKDW ƅUVW PLVVLRQ Š

An academic route into the space sector might
include GCSEs followed by A-Levels, a university
GHJUHH DQG SRVVLEO\ D SRVWJUDGXDWH TXDOLƅFDWLRQ
such as a PhD. This is often the route for a career
LQ DVWURSK\VLFV RU VFLHQWLƅF UHVHDUFK ,I WKLV VRXQGV
like it’s for you, explore courses you’re interested
LQ ƅJXUH RXW ZKDW WKH\ HQWDLO DQG ZKDW WKH HQWU\
requirements are.

Þ ESA’s Astronaut in a university, working with data or giving lectures to Follow your own route
undergraduates and doing public outreach activities.
Application Astronauts only spend a few weeks or months in If your interest lies in astronomy, sciences and maths
Handbook provides space, but undergo years of gruelling training and are important, and most astronomers do a university
great insights into travelling to get there. GHJUHH LQ DVWURSK\VLFV RU D UHODWHG VXEMHFW
the many roles at
the Space Agency “We aren’t looking for supermen and superwomen Sheila Kanani, Education, Outreach and Diversity
and what it takes who are the best at everything, but people who are 2IƅFHU DW WKH 5R\DO $VWURQRPLFDO 6RFLHW\ GLG D
to get them four-year Master’s in Physics and Astrophysics at
the University of Manchester, followed by a PhD
EMPLOYEE PROFILE in Planetary Science at Mullard Space Science
Laboratory. This was followed by teacher training
Christopher Ogunlesi • Job title: PhD student in DQG D MRE DV D IXOO WLPH WHDFKHU
Additive Manufacturing, University of Southampton
“I was able to go to Australia and also worked
Chris worked on the BepiColombo mission to Mercury with the radio telescope at Jodrell Bank, where I
DV DQ (6$ \RXQJ JUDGXDWH WUDLQHH was using pulsar timing data to look for exoplanets
around pulsars,” she says. “It’s been a very winding
“I explore additive manufacturing, which is a fancy career path that led me to where I am today. I’ve
way of saying 3D printing. We’re printing a thruster got a background in education, but also a research
for satellites, which allows us to make complex shapes. 3D printing, background as well, which I think is really important.”
especially of metal, is a relatively new process so a lot about how that
affects materials and their properties isn’t really that well understood.” Astronomers use computers for modelling and
working with data, so computer programming
skills are useful. Join an astronomical society or
attend local talks and events, to immerse yourself >

September 2021 BBC Sky at Night Magazine 39

Professor Stephen Fairhurst (below) gives a
talk on gravitational waves. He’s part of Cardiff
University’s LIGO group, which helped to detect

gravitational waves generated from a
collision of two black holes in 2015

LIGO/T. PYLE, JOHN GAFFEN/ALAMY STOCK PHOTO, STEPHEN KILL/STFC, ESA> in the subject. As an astronomer you’ll conductSurrey Satellite Technology Ltd (SSTL).Þ Scientists from
ILLUSTRATIONresearch into the processes that govern the UniverseThe growth of the space sector depends on
and you may end up studying exoplanets, stars, the University of
black holes, galaxies or the evolution of the early people with the right skills entering the industry, and Leicester have
Universe. Observational astronomers use telescopes apprenticeship schemes help ensure that people with worked on one of
and cameras, analysing data to provide a picture those skills are there to drive the industry forward. the instruments
of what’s happening in the cosmos. Theoretical Apprentices receive on-the-job training while being that will be used on
astronomers use maths and computer modelling to paid for work, and study for at least 20 per cent the James Webb
make predictions and explain observations, helping Space Telescope
to put pieces of the puzzle in place. To become a
professional astronomer, you’ll need to study for a EMPLOYEE PROFILE
PhD in an area of astronomy that interests you. Then
you can apply for jobs in universities, observatories or Chloe Smith • Job title: Apprentice at Surrey Satellite
research institutes around the world. Technology Ltd (SSTL)

Do some research into the universities that Chloe assesses spacecraft parts to ensure they can
have a good reputation for the particular subject withstand space radiation.
you’re interested in. UK universities rated highly for
physics and astronomy include the University of “If you’re not top of the class in your favourite subject,
Oxford, the University of Cambridge, the University don’t let that put you off. If you have a passion for
of St Andrews, the University of Manchester and something, you can make it happen. Having a strong interest in
University College London (UCL). Queen’s University something is more important than being amazing at it. At the end of the
Belfast has a thriving astrophysics research centre day, no one knows everything and you’ll learn along the way.”
with a teaching observatory for those interested in
observational astronomy. Cardiff University is part of
the LIGO (Laser Interferometer Gravitational-Wave
2EVHUYDWRU\ JURXS WKDW PDGH WKH ƅUVW GHWHFWLRQ RI
gravitational waves in 2015. Scientists from the Space
Research Centre at the University of Leicester have
been working on the Mid InfraRed Instrument (MIRI)
on board the James Webb Space Telescope. Spend
time looking at what each university has to offer.

Learn from experience

Work experience schemes such as Space Placements
in INdustry (SPIN) enable you to learn new skills and
try a career on for size. Graduate training schemes
are an excellent way to get into the space industry
and launch your career, while learning valuable skills.
Examples include ESA’s Young Graduate Trainee
Programme (YGT) and schemes with aerospace
companies such as Airbus, QinetiQ, RAL Space and

40 BBC Sky at Night Magazine September 2021

EMPLOYEE PROFILE

Tim Peake • Job title: Astronaut

7LP LV WKH 8.ŝV ƅUVW (6$ DVWURQDXW DQG LV KHDYLO\
HQJDJHG LQ VSDFHƆLJKW RXWUHDFK

“Get involved in science, tech and engineering. It space science. Many schools have a STEM (Science,
doesn’t matter if you want a career in science or art: Technology, Engineering and Maths) club that gives
you’re going to be working with technology. If you you a chance to develop skills and meet like-minded
study those subjects, you’re setting yourself up well for the future, people. Studying subjects such as GCSE Astronomy,
giving yourself the maximum opportunity. But find out what you’re taking part in competitions like the UK Space Design
passionate about: that’s what you’re going to be really good at.” Competition and getting involved in projects like the
National Schools Observatory are all great ways to
of their working hours (usually one day a week), boost your knowledge and skills.
gaining skills and knowledge needed for the job.
Apprenticeships usually last between one and six With many innovative space and astronomy
years and are available at different levels, so you can missions on the horizon, new UK spaceports being
FKRRVH RQH WR VXLW \RX DQG \RXU TXDOLƅFDWLRQV 8. constructed and humans set to return to the Moon
organisations offering apprenticeships include Airbus, to build the Lunar Gateway, it’s an exciting time for
Rolls-Royce, QinetiQ, SSTL, Reaction Engines, RAL astronomy and space exploration. The question is
Space and the National Space Academy. will you be a part of it?

Hayley Smith is a Support for students BBC Bitesize is a free
physics teacher and online resource designed
a Lead Educator UK Students for the Exploration and Development of to help with careers and
at the National Space (UKSEDS) is the UK’s national student space learning. There’s a range
Space Academy society. It provides training and events for students RI LQWHUDFWLYH OHVVRQV YLGHR FOLSV DQG TXL]]HV
with an interest in space. UKSEDS has a careers hub WR KHOS ERRVW \RXU NQRZOHGJH LQ DOO VXEMHFWV
(spacecareers.uk) with details of jobs and internships, LQFOXGLQJ SK\VLFV DQG VSDFH VFLHQFH DV ZHOO DV
interviews with people working in the sector and a huge range of careers resources including job
resources to help you map out a career path. If you’re SURƅOHV LQWHUYLHZV DQG &9 ZULWLQJ WLSV
after a direct-entry job, it’s a great place to start. See more at www.bbc.co.uk/bitesize

Summer schools, such as Space School UK, run
programmes for young people with an interest in

Þ ESA’s YGT (Young Graduate Trainee) Programme offers students a chance to gain valuable experience in space mission operations

September 2021 BBC Sky at Night Magazine 41

MASTERCLASS

ASTROPHOTOGRAPHY SERIES

To give you your best start in photographing the night WR DVWURSKRWRJUDSK\ RU D VHDVRQHG LPDJHU WKHUHŝV DOZD\V
VN\ ZHŝUH UXQQLQJ RXU ƅUVW RQOLQH 0DVWHUFODVV WKH VRPHWKLQJ WR OHDUQ DQG RXU RQOLQH PDVWHUFODVVHV DUH WKH SHUIHFW
$VWURSKRWRJUDSK\ 6HULHV 7KLV WKUHH SDUW VHULHV RI WDONV ZD\ WR SLFN XS WLSV KLQWV DQG D UDIW RI VNLOOV $OO UHJLVWUDQWV
ZLOO DUP \RX ZLWK WKH NQRZOHGJH DQG PHWKRGV IRU WDNLQJ ZLOO DOVR UHFHLYH D OLQN WR YLHZ D UHFRUGLQJ RI HDFK 0DVWHUFODVV
VWXQQLQJ LPDJHV RI WKH QLJKW VN\ ZLWK D VPDUWSKRQH D '6/5 DIWHU LW KDV DLUHG <RX FDQ ERRN HDFK 0DVWHUFODVV LQGLYLGXDOO\
FDPHUD DQG VSHFLDOLVW DVWUR FDPHUDV :KHWKHU \RXŝUH QHZ IRU d RU VDYH SHU FHQW E\ ERRNLQJ DOO WKUHH DW RQFH

Join host and Editor Chris Bramley for the three-part series of online
masterclasses on astrophotography, featuring these three expert guests

Masterclass 1 Masterclass 2 Masterclass 3 M-GUCCI/ISTOCK/GETTY IMAGES, MATT_GIBSON/ISTOCK/GETTY IMAGES, PETER JENKINS

Capture the night sky Night sky photography Imaging the deep sky
with your smartphone
with a DSLR camera from towns and cities
Tom Kerss
Charlotte Daniels Peter Jenkins
-RLQ XV WR GLVFRYHU KRZ
WR FDSWXUH WKH QLJKW VN\ ,I \RX ZDQW WR WXUQ D '6/5 :HŝOO ORRN DW KRZ \RX FDQ
ZLWK \RXU VPDUWSKRQH FDPHUD WR WKH VWDUV WKLV LV FXW WKURXJK XUEDQ VN\
:HŝOO ORRN DW VXLWDEOH WKH WDON IRU \RX :HŝOO ORRN JORZ ZLWK D VFRSH DQG D
WDUJHWV DQG WRS DSSV DW WDNLQJ QLJKWVFDSHV DQG VSHFLDOLVW DVWUR FDPHUD
to try out. VWDU ƅHOGV HTXLSPHQW DQG KRZ SURFHVVLQJ
DQG SURFHVVLQJ FDQ KHOS HYHQ IXUWKHU
Thursday 23 September, 7pm BST
Thursday 28 October, 7pm BST Thursday 25 November, 7pm GMT

Save 20% when you book the series
of all three masterclasses

Visit skyatnightmagazine.com/virtual-events to find out more and book

16-PAGE
CENTRE
PULLOUT

The Sky Guide

SEPTEMBER 2021

HUNT FOR THE
SLENDER MOON

Two excellent opportunities this month,
thanks to a good phase and position

PETE LAWRENCE MINOR PLANET AHOY

Observe asteroid 2 Pallas as
it reaches opposition in Pisces

LOCATE A ‘LUNAR CITY’

Spot the streets of Gruithuisen’s
imaginary metropolis

About the writers Also on view Red light friendly Get the Sky
this month… Guide weekly
Astronomy Steve To preserve your night
expert Pete Tonkin is ✦ Shadow transits by vision, this Sky Guide For weekly updates on
Lawrence is a binocular Jupiter’s Galilean moons can be read using a red what to look out for in
a skilled astro observer. light under dark skies the night sky and more,
imager and Find his tour ✦ Mercury at greatest sign up to our newsletter
a presenter on The Sky at of the best sights for eastern elongation at www.skyat
Night monthly on BBC Four both eyes on page 54 nightmagazine.com
✦ A conjunction of Jupiter,
Saturn and the Moon

September 2021 BBC Sky at Night Magazine 43

SEPTEMBER HIGHLIGHTS Yourguidetothe
night sky this month

W Wednesday Thursday

1 A telescopic view of 2 This morning’s
Jupiter this morning 24%-lit waning
will reveal the outer crescent Moon occults
Galilean moon, Callisto, mag. +3.0 Mebsuta
transiting the planet’s disc (Epsilon (¡) Geminorum) from
from 02:33 BST (01:33 UT). 01:12 BST (00:12 UT) until
Jupiter sets before the transit 02:04 BST (01:04 UT). These
ends. See page 47 for more. times are correct for the
centre of the UK and will
vary slightly with location.

Monday X

6 There’s an excellent
opportunity to spot
a less than 1%-lit thin
crescent Moon this
PRUQLQJ ,W LV ORFDWHG Ō WR
the left of, and fractionally
down from, Regulus (Alpha
(_) Leonis). The Moon rises
75 minutes before the Sun.
See page 46 for more.

W Friday Saturday

10 Around 11 Asteroid 2
midnight BST Pallas reaches
(23:00 UT), extend opposition today
the east side of the in the constellation
Great Square of Pegasus (left of Pisces, the Fishes. Shining
from the UK) down to locate at mag. +8.5, 2 Pallas is a
bright Deneb Kaitos (Beta (`) viable binocular target.
&HWL Ō VRXWK DQG D IUDFWLRQ Turn to page 53 for more.
east of this star lies a treat – the
mag. +7.1 Sculptor Galaxy.

Tuesday X

14 Mercury reaches
greatest eastern
elongation. Today, it
will appear separated
IURP WKH 6XQ E\ Ō LQ WKH
evening sky. Poor positioning
means mag. +0.3 Mercury will
set 20 minutes after the Sun.

Neptune reaches opposition.

PETE LAWRENCE X 7 Family stargazing W Wednesday

The ‘Lunar X’ and ‘Lunar V’ are examples of clair-obscur 22 At 20:21 BST (19:21
effects; tricks of light and shadow which creates familiar UT) the centre of
shapes. In this case, it’s the letters X and V that appear the Sun’s disc
along the line dividing light and dark on the Moon’s globe – the crosses the
terminator. Visible for just a few hours, both letters are best seen celestial equator moving
at 21:30 BST (20:30 UT) on 13 September, the ‘X’ roughly from north to south. This
one-quarter up the terminator from the Moon’s southern edge, instant in time is known
the ‘V’ slightly north of the mid-point. Using binoculars or a as an equinox and for the
scope, can you see the letters suspended in the dark against the Northern Hemisphere it
terminator? www.bbc.co.uk/cbeebies/shows/stargazing marks the start of autumn.

44 BBC Sky at Night Magazine September 2021

Friday Saturday Sunday NEED TO

3 This morning’s 4 This morning’s 5 Catch two good KNOW
16%-lit waning 9%-lit waning transits by Jupiter’s
moons and their shadows. The terms and symbols
crescent Moon occults OXQDU FUHVFHQW LV MXVW Ō Europa begins to transit used in The Sky Guide
at 23:12 BST (22:12 UT), followed
mag. +3.6 Kappa (g) from the Beehive Cluster, by its shadow at 00:04 BST Universal Time (UT)
Geminorum from 03:41 BST (23:04 UT). Ganymede starts to and British Summer
M44, at 04:10 BST (03:10 UT). transit at 02:03 BST (01:03 UT) , Time (BST)
(02:41 UT) until 04:38 BST on 6 September, its shadow
following at 03:47 BST (02:47 Universal Time (UT) is
(03:38 UT). UT). See page 47. the standard time used
by astronomers around
Tuesday Thursday the world. British
Summer Time (BST) is
7 There’s another 9 look above one hour ahead of UT
opportunity to the west-
spot an ultra-thin southwest horizon this RA (Right ascension)
Moon this evening. evening, shortly after and dec. (declination)
Look low down above the sunset, to locate a 9%-lit
western horizon after sunset waxing crescent Moon, mag. These coordinates are the
to spot this less than 1%-lit –4.0 Venus and the bright night sky’s equivalent of
waxing crescent. It will set white mag. +1.0 star Spica longitude and latitude,
about 35 minutes after the (Alpha (_) Virginis). See page describing where an object
Sun. See page 46 for more. 46 for more. is on the celestial ‘globe’

Monday Family friendly

13 A telescopic Objects marked
view of this with this icon are perfect
evening’s first for showing to children
quarter Moon
around 21:30 BST (20:30 UT) Naked eye
will reveal the clair-obscur
effects known as the ‘Lunar Allow 20 minutes
X’ and ‘Lunar V’; two giant for your eyes to become
letter shapes floating next to dark-adapted
the lunar terminator.
Photo opp
Friday Monday X
Use a CCD, planetary
17 At 22:30 BST 20 Today’s full camera or standard DSLR
(21:30 UT) Moon is the
an 89%-lit waxing closest full Moon Binoculars
gibbous Moon is to the Northern
near Saturn and Jupiter. Hemisphere’s autumn equinox. 10x50 recommended
Consequently, this will be
A shadow transit of Jupiter’s the Harvest Moon for 2021. Small/
disc by its moon Callisto medium scope
starts at 23:43 BST (22:43 UT).
See page 47 for more. Reflector/SCT under 6 inches,
refractor under 4 inches

Large scope

Reflector/SCT over 6
inches, refractor over 4 inches

Monday Gruithuisen’s W Wednesday GETTING STARTED
Lunar City
27 Catch a 29 Viewing the IN ASTRONOMY
daylight Schröter W last quarter
shadow transit Moon with a scope If you’re new to
of Ganymede this morning, can astronomy, you’ll find
from 15:49 BST (14:49 UT) you spot what was once two essential reads on our
until 19:25 BST (18:25 UT). believed to be a ruined city? website. Visit http://bit.
The end of the event The clair-obscur effect known ly/10_easylessons for our
occurs in darkening evening as ‘Gruithuisen’s Lunar City’ is 10-step guide to getting
twilight. See to page 47 visible, north of crater Schröter started and http://bit.ly/
for more. W. See page 47 for more. buy_scope for advice
on choosing a scope

September 2021 BBC Sky at Night Magazine 45

THE BIG THREE The three top sights to observe or image this month

DON’T MISS e M35 1

THE MOON GEMINI Mebsuta d
disappears:
2 Sep, 01:12 BST
(00:12 UT)

BEST TIME TO SEE: Multiple events, Castor l ¡ +
dates and times as specified o i
_
7KH 0RRQ SXWV RQ D ƅQH GLVSOD\ RI Mebsuta Mebsuta
YDULHG HYHQWV GXULQJ 6HSWHPEHU 2Q reappears:
WKH PRUQLQJ RI WKH QG VWDUWLQJ DW 2 Sep, 02:04 BST

f (01:04 UT)

%67 87 WKH OLW ZDQLQJ Pollux p c Alhena
FUHVFHQW 0RRQ RFFXOWV PDJ 0HEVXWD
(SVLORQ ¡ *HPLQRUXP Ś ZKHQ WKH ` Kappa Geminorum a
0RRQŝV SRVLWLRQ KLGHV RXU YLHZ RI WKH VWDU
b

IURP (DUWK 7KH VWDUŝV UHDSSHDUDQFH g Kappa Gem j
RFFXUV DURXQG %67 87 DV disappears:
YLHZHG IURP FHQWUH RI WKH 8. DOWKRXJK Kappa Gem 3 Sep, 03:41 BST
WLPHV ZLOO YDU\ VOLJKWO\ ZLWK ORFDWLRQ 2Q reappears: (02:41 UT)
WKH PRUQLQJ RI WKH UG PDJ .DSSD
g *HPLQRUXP LV RFFXOWHG E\ WKH QRZ 3 Sep, 04:38 BST
(03:38 UT)

h

OLW ZDQLQJ FUHVFHQW 0RRQ 9LHZHG

IURP WKH FHQWUH RI WKH 8. LW GLVDSSHDUV DW

%67 87 DQG UHDSSHDUV DW Þ The Moon occults Mebsuta (on 2 September) and Kappa Geminorum (on 3 September)

%67 87 LQ PRUQLQJ WZLOLJKW

2Q WKH PRUQLQJ RI 6HSWHPEHU QRZ DW VN\ 2Q WKH PRUQLQJ RI WKH WK WKH OLW LVQŝW VR RSWLPDO DQG DOWKRXJK WKLV WKLQ

D OLW ZDQLQJ FUHVFHQW SKDVH WKH 0RRQ ZDQLQJ FUHVFHQW 0RRQ ULVHV PLQXWHV OXQDU FUHVFHQW LV VOLJKWO\ IXUWKHU IURP WKH

OLHV FORVH WR WKH EHDXWLIXO %HHKLYH &OXVWHU EHIRUH WKH 6XQ 7KH SRVLWLRQ IRU WKLV 6XQ LQ WKH VN\ WKDQ LW ZDV RQ WKH PRUQLQJ

0 LQ &DQFHU WKH &UDE $W %67 FKDOOHQJLQJ FUHVFHQW FRXOGQŝW EH EHWWHU RI WKH WK LW ZLOO VHW MXVW PLQXWHV DIWHU

87 WKH FHQWUH RI WKH 0RRQ VLWV WKH 0RRQ ULVLQJ DOPRVW YHUWLFDOO\ DERYH WKH 6XQ

Ō IURP WKH FHQWUH RI WKH RSHQ FOXVWHU WKH SRVLWLRQ RI WKH 6XQ $IWHU SDVVLQJ QHZ 7ZR QLJKWV ODWHU RQ 6HSWHPEHU LWŝV

7KH 0RRQ DSSHDUV DV DQ XOWUD WKLQ 0RRQ DW %67 87 RQ WKH WK SRVVLEOH WR VHH D QRZ OLW ZD[LQJ

FUHVFHQW RQ WKH PRUQLQJ RI 6HSWHPEHU WKDW HYHQLQJ WKHUHŝV DQ RSSRUWXQLW\ WR FUHVFHQW 0RRQ ORFDWHG DSSUR[LPDWHO\

DQG WKH HYHQLQJ RI WKH WK YLVLEOH DJDLQVW VSRW WKH XOWUD WKLQ ZD[LQJ FUHVFHQW 0RRQ Ō IURP PDJ Ś 9HQXV ORZ LQ WKH

WKH EULJKW YLJQHWWH RI WKH GDZQ DQG GXVN DIWHU VXQVHW 7KH SRVLWLRQ RI WKLV 0RRQ ZHVW VRXWKZHVW DIWHU VXQVHW 7KH WZR

REMHFWV IRUP DQ LQWHUHVWLQJ GRZQ SRLQWLQJ

WULDQJOH ZLWK PDJ 6SLFD $OSKD _

9LUJLQLV ORFDWHG FORVH WR WKH KRUL]RQ

EHORZ WKH 0RRQ DQG 9HQXV

2Q WKH HYHQLQJ RI WKH WK D WHOHVFRSLF

YLHZ RI WKH 0RRQ DW %67 87

UHYHDOV WKH SRSXODU Ŝ/XQDU ;ŝ DQG Ŝ/XQDU 9ŝ

FODLU REVFXU HIIHFWV WKDW DSSHDU QHDU WKH

WHUPLQDWRU 7KH Ŝ/XQDU ;ŝ LV FDXVHG E\ WKH

SDUWLDO OLJKWLQJ RI WKH ULPV RI WKH FUDWHUV

/D &DLOOH 3XUEDFK DQG %ODQFKLQXV DQG

WKH Ŝ/XQDU 9ŝ DSSHDUV QHDU WKH FUDWHU

ALL PICTURES: PETE LAWRENCE 8NHUW 2Q 6HSWHPEHU WKH OHVV IDPLOLDU

DQG FKDOOHQJLQJ FODLU REVFXU HIIHFW NQRZQ

DV Ŝ*UXLWKXLVHQŝV /XQDU &LW\ŝ LV YLVLEOH QHDU

WKH FUDWHU 6FKU¶WHU : VHH RSSRVLWH

)LQDOO\ IXOO 0RRQ RQ 6HSWHPEHU

RFFXUV D FRXSOH RI GD\V EHIRUH WKH

1RUWKHUQ +HPLVSKHUHŝV DXWXPQ HTXLQR[

Þ Catch a 1%-lit waning crescent Moon rising 75 minutes before the Sun on 6 September PDNLQJ LW WKH +DUYHVW 0RRQ IRU

46 BBC Sky at Night Magazine September 2021

Galilean Europa transit: Timings for
satellite events 23:12-02:00 BST 5/6 September
(22:12-01:00 UT) Ganymede transit:
BEST TIME TO SEE: Multiple events, 02:03-05:35 BST (01:03-04:35 UT)
dates and times as specified Ganymede shadow transit:
03:47-07:20 BST (02:47-06:20 UT)

S

(DUWKŝV 0RRQ LV QRW WKH RQO\ RQH WR Io emerges from Jupiter sets
SXW RQ D VKRZ WKLV PRQWK -XSLWHUŝV eclipse at 00:38 BST around 04:35
PRRQV DUH SXWWLQJ RQ VRPHWKLQJ RI D (23:38 UT), and appears BST (03:35 UT)
GLVSOD\ WRR 7KH RXWHU *DOLOHDQ PRRQ 5 arcseconds from Ganymede
&DOOLVWR ZLOO EH WUDQVLWLQJ -XSLWHUŝV GLVF RQ at 00:53 BST (23:53 UT)
6HSWHPEHU IURP %67 87
XQWLO -XSLWHU VHWV $ IHZ GD\V ODWHU Europa shadow transit:
VWDUWLQJ RQ WKH HYHQLQJ RI 6HSWHPEHU 00:04-02:50 BST (23:04-01:50 UT)
WKHUH DUH WZR JRRG VDWHOOLWH DQG VKDGRZ
WUDQVLWV RFFXUULQJ LQ TXLFN VXFFHVVLRQ 7KH Þ A south-up view of transit activity on Jupiter at 02:00 BST (01:00 UT) on 6 September
HYHQWV VWDUW DW %67 87 ZLWK
(XURSDŝV WUDQVLW IROORZHG E\ LWV VKDGRZ DW ZHVW VRXWKZHVW KRUL]RQ DURXQG %67 EHORZ WKH JDV JLDQW IRUPLQJ D WULDQJOH
%67 87 *DQ\PHGH VWDUWV WR 87 JLYLQJ SOHQW\ RI WLPH WR WDNH LQ ZLWK -XSLWHU DQG 6DWXUQ
WUDQVLW DW %67 87 IROORZHG E\ WKH EHVW SDUWV RI WKLV OHDVW FRPPRQ RI
LWV RZQ VKDGRZ DW %67 87 DOO WKH *DOLOHDQ PRRQ VKDGRZ WUDQVLWV $ WUDQVLW RI *DQ\PHGHŝV VKDGRZ RFFXUV
&DOOLVWR RQFH DJDLQ JLYHV XV D GLVSOD\ &DOOLVWRŝV VKDGRZ LV PRUH RU OHVV FHQWUDO RQ WKH WK 0RVW RI WKLV HYHQW RFFXUV
RQ WKH WK ZKHQ LWV JLDQW VKDGRZ FDQ EH RQ -XSLWHUŝV GLVF DURXQG %67 EHIRUH -XSLWHU ULVHV ZLWK WKH VKDGRZ
VHHQ FURVVLQJ -XSLWHUŝV GLVF LQ D ZHOO WLPHG 87 ZKHQ -XSLWHU ZLOO KDYH DQ DOWLWXGH RYHU WKH KDOIZD\ SRLQW XQGHU GD\OLJKW
HYHQW IRU 8. YLHZLQJ 7KH HYHQW VWDUWV DW DURXQG Ō DERYH WKH VRXWKZHVW KRUL]RQ FRQGLWLRQV DV -XSLWHU DSSHDUV &DWFK LW
%67 87 EXW FRQFOXGHV $Q OLW ZD[LQJ JLEERXV 0RRQ VLWV EHIRUH %67 87 DQG VHH WKH
VKRUWO\ DIWHU -XSLWHU VHWV -XSLWHU KLWV WKH VKDGRZ DV LW QHDUV -XSLWHUŝV ZHVWHUQ OLPE

Gruithuisen’s Lunar City

BEST TIME TO SEE: Gruithuisen’s Locate the crater Schröter W (left) and
Lunar City see if you can make out the streets
29 September from of Gruithuisen’s Lunar City just to
Schröter W the north-northeast
05:00 BST (04:00 UT)
Schröter Schröter W
7KHUHŝV DQ RSSRUWXQLW\ Mosting
WR VSRW WKH OHVV FRPPRQ N
FODLU REVFXU HIIHFW NQRZQ DV E
*UXLWKXLVHQŝV /XQDU &LW\ RQ WKH
PRUQLQJ RI WKH WK :LWK VXFK LVRVFHOHV WULDQJOH 7KH HQFRXQWHU KHDYLO\ HURGHG *UXLWKXLVHQŝV FLW\ DSSHDU WR
DQ HQLJPDWLF VRXQGLQJ QDPH VRXWKHUQ YHUWH[ FORVH WR WKH NP 6FKU¶WHU .HHS WUDYHOOLQJ UDGLDWH QRUWK RI 6FKU¶WHU :
\RX PLJKW H[SHFW WKH YLHZ PRUQLQJ WHUPLQDWRU LV PDUNHG WRZDUGV (UDWRVWKHQHV DQG WKH LQ D IDQ OLNH DUUDQJHPHQW
WKURXJK D WHOHVFRSH H\HSLHFH E\ NP 0RVWLQJ QH[W VPDOO LGHQWLƅDEOH FUDWHU
WR EH JUDQGLRVH EXW LWŝV QRW LV NP 6FKU¶WHU : ZLWK D 7KH HIIHFW LV QDPHG DIWHU
7KH ŜFLW\ŝ LV IRUPHG E\ VXEWOH )URP 0RVWLQJ KHDG EDFN VPDOOHU FUDWHU NP 6FKU¶WHU $ DVWURQRPHU )UDQ] YRQ 3DXOD
OLJKW DQG VKDGRZ SOD\ ZKLFK WRZDUGV (UDWRVWKHQHV 5RXJKO\ LQVLGH LW 7KH ŜVWUHHWVŝ RI *UXLWKXLVHQ ZKR GLVFRYHUHG
FDQ EH KDUG WR VHH 2I FRXUVH RQH ƅIWK WKH ZD\ \RXŝOO WKH Ŝ/XQDU &LW\ŝ LQ
WKLV PDNHV LW DQ LUUHVLVWLEOH
DVWURQRPLFDO FKDOOHQJH
,WŝV SRVVLEOH WR QDYLJDWH WR
WKH ŜFLW\ŝ YLD VHYHUDO GLVWLQFWLYH
FUDWHUV LQFOXGLQJ NP
&RSHUQLFXV DQG NP
(UDWRVWKHQHV ,PDJLQH WKHP
IRUPLQJ RQH VLGH RI D ODUJH

September 2021 BBC Sky at Night Magazine 47

THE PLANETS Our celestial neighbourhood in September

PICK OF THE Circlet PISCES Imagine Psi (q), HIP 115257 and 90 Aquarii as an
arrowhead, with 20 Piscium at the bottom of
MONTH
the shaft. A triangle of stars, HIP 115953, 116106
and 116266, lies about halfway along the shaft,

and this is a guide to locating Neptune.

14

Neptune HIP 116106 90
HIP 115953
Best time to see: 14 September,
01:00 BST (00:00 UT) 20 1 Sep 30 Sep ij
Altitude: 33º
Location: Aquarius Neptune HIP 115257
Direction: South
Features: Small blue-hued disc, HIP 116266
atmospheric features
Recommended equipment: AQUARIUS
200mm or larger
1
8QGHU WKH FXUUHQW GHƅQLWLRQ RI D SODQHW
Neptune is the farthest such object in 2
our Solar System. It orbits the Sun at a 3
distance of 4.5 billion kilometres, taking
164.8 years to complete each orbit. It was A power of 200x or greater is Smaller instruments will
discovered by Johann Galle and Urban Le
Verrier on 23 September 1846 and as such recommended to show this show the planet’s blue disc
has only completed one orbit around the
Sun since its discovery. Neptune is the disc well. The planet’s as described, but may
only main planet not visible to the naked
eye, although its Solar System neighbour, colour, like the green also be able to pick
Uranus, is hardly easy in this respect!
hue of Uranus, is quite out Neptune’s largest
Neptune is currently located in
Aquarius, roughly midway between striking, Neptune being moon, Triton. Shining
mag. +4.2 Psi (q Aquarii and mag. +5.5
20 Piscium. Binoculars will show it to noticeably blue. at mag. +13.5, Triton
look exactly like a mag. +7.8 star, but its
planetary nature becomes more evident Neptune reaches is an easy catch for a
through the eyepiece of a telescope.
Neptune shows a tiny 2 arcsecond disc. opposition on the 300mm instrument,

14th although being but isn’t out of range of

so distant, this optimal smaller scopes; 200mm is

position in the sky probably the minimum.

PETE LAWRENCE X 3 doesn’t make a great Þ When Neptune reaches /DUJHU VFRSHV ƅWWHG
deal of difference to with specialist high-
the planet’s overall opposition on 14 September, resolution imaging kit
appearance. It does it will be visible all night long may occasionally pick

mean it’s up all night long though, so this out large detail on Neptune’s disc such as

is as good a time as ever to look for it. atmospheric banding and storm systems.

The planets in September The phase and relative sizes of the planets this month. Each planet is shown
with south at the top, to show its orientation through a telescope

Venus Mars Jupiter Saturn Uranus Neptune
15 Sep 15 Sep 15 Sep 15 Sep 15 Sep 15 Sep

Mercury 0 10 20 30 40 50 60
1 Sep ARCSECONDS

Mercury
15 Sep

Mercury
30 Sep

48 BBC Sky at Night Magazine September 2021

Mercury highest position in the sky, due JUPITER’S MOONS: SEP
south, in darkness during the
Best time to see: 1 September, month. It’s apparent position Using a small scope you can spot Jupiter’s biggest moons. Their
15 minutes after sunset in the sky has it travelling west positions change dramatically during the month, as shown on the
Altitude: 2Ō (very low) through the eastern part of diagram. The line by each date represents 01:00 BST (00:00 UT).
Location: Virgo Capricornus, the Sea Goat and
Direction: West this will reduce its overall DATE WEST EAST
Mercury is an evening object altitude over the month. On
during September, but its the 1st, from the centre of the 1
position deteriorates over the UK, Jupiter attains an altitude 2
month. Your best chance of of 22.9Ō. By the 30th, this value 3
spotting it will be on the 1st will have dropped to 22.0Ō. 4
when, shining at mag. 0.0, it 5
sets 30 minutes after the Sun, Saturn 6
below the western horizon. This 7
doesn’t give you long to locate Best time to see: 1 September, 8
it. Venus is also low in this 23:10 BST (22:10 UT) 9
direction, 16Ō east of Mercury’s Altitude: 18Ō 10
position. By the end of the Location: Capricornus 11
month, mag. +1.5 Mercury Direction: South 12
virtually sets with the Sun. Being at opposition at the 13
start of August and with the 14
Venus rapidly expanding nights that 15
occur during September, 16
Best time to see: 1 September, Saturn remains nicely placed, 17
from 20 minutes after sunset able to attain its maximum 18
Altitude: 5Ō (low) altitude of around 18Ō from the 19
Location: Virgo centre of the UK under dark 20
Direction: West-southwest sky conditions all month long. 21
Venus is visible in the evening On the 1st, mag. +0.3 Saturn 22
sky after sunset, appearing reaches its highest point in the 23
higher than Mercury and much sky, due south, at 23:10 BST 24
brighter. At the start of the (22:10 UT). By the month’s 25
month Venus shines at mag. end, this position is reached 26
–4.0. By the end of the month at 21:10 BST (20:10 UT). 27
it increases in brilliance to 28
mag. –4.2. Venus sets Uranus 29
approximately 1 hour after the 30
Sun throughout the month. Best time to see: 30 September, 1
03:15 BST (02:15 UT)
*LYHQ D ƆDW ZHVW VRXWKZHVW Altitude: 53Ō 8 76 54 3 2 1 01 2 34 5 6 78
horizon, it may be possible to Location: Aries arcminutes
spot Spica (Alpha (_) Virginis) Direction: South
1.6Ō below Venus on the Uranus is well placed, reaching Jupiter Io Europa Ganymede Callisto
evening of the 5th. a position of 50Ō in total
darkness in the morning sky.
Mars It currently resides in Aries, the
Ram and is not too far from
Shining with a magnitude of the Pleiades open cluster, the
+1.8, Mars isn’t really a viable cluster being 16Ō east-northeast
target this month as it is too of Uranus. By the month’s end,
close to the Sun to be seen. Uranus reaches a maximum
height of 52Ō in darkness when
Jupiter due south as seen from the
centre of the UK.
Best time to see: 1 September,
00:20 BST (23:20 UT) More ONLINE
Altitude: 22.9Ō
Location: Capricornus Print out observing forms for
Direction: South recording planetary events
Jupiter is an evening planet,
managing to achieve its

September 2021 BBC Sky at Night Magazine 49

THE NIGHT SKY – SEPTEMBER

Explore the celestial sphere with our Northern Hemisphere all-sky chart NORT

KEY TO When to use this chart HEAST
STAR CHARTS
1 September at 01:00 BST
Arcturus STAR NAME 15 September at 00:00 BST
30 September at 23:00 BST
PERSEUS AURIGA` b
On other dates, stars will be in slightly different positions
CONSTELLATION because of Earth’s orbital motion. Stars that cross the AlphaPAeaukrig1iSdesp
NAME sky will set in the west four minutes earlier each night. M38M36 M37
GALAXY
_
OPEN CLUSTER
How to use this chart UV Capella
GLOBULAR Kids
CLUSTER 1. Hold the chart ` TAURUS
so the direction
PLANETARY you’re facing is
NEBULA at the bottom.

DIFFUSE 2. The lower half _ k
NEBULOSITY of the chart
shows the sky b
DOUBLE STAR ahead of you. _ PERSEUS
VARIABLE STAR
3. The centre of Aldebaran Algol
the chart is the M3
THE MOON, point directly b Hyades Pleiades M45 `
SHOWING PHASE over your head. a TRIANGULUM

COMET TRACK APlepahka1T1r/i1a2nSgeuplids

Sunrise/sunset in September* EAST Hamal

ASTEROID Date Sunrise Sunset 25th ` PIS
TRACK _ 22nd
1 Sep 2021 06:19 BST 19:59 BST CETUS
STAR-HOPPING 11 Sep 2021 06:37 BST 19:35 BST a
PATH 21 Sep 2021 06:54 BST 19:11 BST `
01 Oct 2021 07:12 BST 18:46 BST _
METEOR ARIES Deneb
RADIANT Kaitos
Uranus
Moonrise in September* `
Circlet a
ASTERISM Moonrise times a Ecliptic
_ Menkar
1 Sep 2021, --:-- BST 17 Sep 2021, 18:44 BST
PLANET 5 Sep 2021, 03:48 BST 21 Sep 2021, 19:47 BST
9 Sep 2021, 09:23 BST 25 Sep 2021, 20:42 BST
13 Sep 2021, 15:13 BST 29 Sep 2021, 23:04 BST b

QUASAR _

*Times correct for the centre of the UK Mira

STAR BRIGHTNESS: k T

MAG. 0 Lunar phases in September
& BRIGHTER
Saturday Sunday Monday Tuesday Wednesday Thursday Friday
1 23
MAG. +1

MAG. +2 4 5 6 7 8 9 10 SOUTHEAS

MAG. +3 NEW MOON

MAG. +4 11 12 13 14 15 16 17
& FAINTER

5º N W COMPASS AND
E FIELD OF VIEW

CHART: PETE LAWRENCE S 18 19 20 21 22 23 24

MILKY WAY FULL MOON

25 26 27 28 29 30

50 BBC Sky at Night Magazine September 2021