APPENDIX 1: Astronomy Ranking Task: Phases of the Moon

APPENDIX
1: Astronomy Ranking Task: Phases of the Moon

Exercise #1
Description: The figure below shows a “top view” of the Sun, Earth, and five different positions
(A - E) of the Moon during one orbit of Earth. Note that the distances shown for the Sun to Earth
and for Earth to the Moon are not drawn to scale.

A. Ranking Instructions: Rank (from greatest to least) the amount of the Moon’s entire surface
that is illuminated by sunlight for the five positions (A-E) shown.

Ranking Order: Greatest 1 ____ 2 ____ 3 ____ 4____ 5 ____ Least
Or, the amount of the entire surface of the Moon illuminated by sunlight is the same at all the
positions. ____ (indicate with check mark).
Carefully explain your reasoning for ranking this way:
________________________________________________________________________
________________________________________________________________________
B. Ranking Instructions: Rank (from greatest to least) the amount of the Moon’s illuminated
surface that is visible from Earth at each of the five positions (A – E) shown.
Ranking Order: Greatest 1 ___ 2 ____ 3 ____ 4 ____ 5 ____ Least
Or, the amount of the Moon’s illuminated surface visible from Earth is the same in all positions.
_____ (indicate with check mark).
Carefully explain your reasoning for ranking this way: ___________________________
________________________________________________________________________

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APPENDIX

2: Astronomy Ranking Task: Phases of the Moon

Exercise #2

Description: Shown below are five different phases of the Moon (A–E) as seen by an observer
in the northern hemisphere.

AB C D E

A. Ranking Instructions: Beginning with the waxing gibbous phase of the Moon, rank the
moon phases shown below in the order that the observer would see them over the next four
weeks.

Ranking Order:

First phase following waxing gibbous phase 1 ___ 2 ____ 3 ___ 4 ____ 5 ____ Last phase seen.

Or, all of these phases would be visible at the same time. _____ (indicate with check mark).

Carefully explain your reasoning for ranking this way:
________________________________________________________________________
________________________________________________________________________
_______________________________________________________________________
_______________________________________________________________________

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APPENDIX

3. Astronomy Ranking Task: Luminosity of Stars

Exercise #1
Description: Imagine you are comparing the five electric hot plates (A–E) of different sizes and
temperatures. The temperature of each hot plate is indicated by a shade of gray such that the
lighter the shade of gray, the higher the temperature of the hot plate.

B C DE
A
A. Ranking instructions: Rank the surface area (from largest to smallest) of the hotplates.
Ranking Order: Largest 1 ____ 2 ____ 3 ____ 4 _____ 5 _____Smallest
Or, all the hotplates have the same surface area. _____ (indicate with a check mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________
B. Ranking instructions: Rank the temperature (from hottest to coldest) of the hotplates.
Ranking Order: Hottest 1 ____ 2 ____ 3 ____ 4 _____ 5 _____ Coldest
Or, all the hotplates have the same temperature _____ (indicate with a check mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________
C. Ranking instructions: Rank the total energy output or luminosity (from greatest to least) of
the hotplates.
Ranking Order: Greatest 1 ____ 2 ____ 3 ____ 4 _____ 5 _____ Least
Or, all the hotplates have the same energy output or luminosity. _____ (indicate with a check
mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________

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APPENDIX
4. Astronomy Ranking Task: Luminosity of Stars

Exercise #2
Description: Consider the Hertzsprung-Russell (HR) diagram shown below which relates the
luminosity (in solar units) to the temperature for four stars (A - D).

A. Ranking instructions: Rank the temperature of the stars (A – D) from hottest to coldest.
Ranking Order: Hottest 1 ____ 2 ____ 3 ____ 4 _____ Coldest
Or, all the stars have the same temperature. _____ (indicate with a check mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________
B. Ranking instructions: Rank the luminosity of the stars (A – D) from greatest (brightest) to
least (dimmest).
Ranking Order: Greatest 1 ____ 2 ____ 3 ____ 4 _____ Least
Or, all the stars have the same luminosity. _____ (indicate with a check mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________
C. Ranking instructions: Rank the surface area of the stars (A – D) from largest to smallest.
Ranking Order: Largest 1 ____ 2 ____ 3 ____ 4 _____ Smallest
Or, all the stars have the same surface area. _____ (indicate with a check mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________

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APPENDIX

5. Astronomy Ranking Task: Luminosity of Stars

Exercise #3
Description: The temperature and surface area for six stars (A - F) are given in the table below.
The temperature of each star is also indicated by a shade of gray such that the lighter the shade of
gray, the higher the temperature of the star.

Star A B C D E F
Surface Area 1 1 2 2 2 4
Temperature 1000 K 2000 K 2000 K 3000 K 1000 K 2000 K

Ranking instructions: Rank the luminosity of the stars (A – F) from greatest (brightest) to least
(dimmest).

Ranking Order: Greatest 1 ____ 2 ____ 3 ____ 4 _____ 5 _____ 6 _____ Least

Or, all the stars have the same luminosity. _____ (indicate with a check mark)

Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________

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APPENDIX
6. Astronomy Ranking Task: Scale of the Universe

Description: Consider the images of six different astronomical objects (A-F) below.

A. The Moon B. The Sun C. Spiral Galaxy

F. The Solar System

D. Neutron Star E. Nebula

A. Ranking Instructions: Rank the objects in terms of size from smallest to largest. Assume
that objects are a “typical” size for that type of object.

Ranking Order: Smallest 1 ____ 2 ____ 3 ____ 4 ____ 5 ____ 6 ____ Largest
Or, all the objects are the same size. _____ (indicate with a check mark)

Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________

B. Ranking Instructions: Rank the objects in terms of mass from least to most. Assume that
objects are a “typical” mass for that type of object.

Ranking Order: Least 1 ____ 2 ____ 3 ____ 4 ____ 5 ____ 6 ____ Most

Or, all the objects are the same mass. _____ (indicate with a check mark)

Carefully explain your reasoning for ranking this way:

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APPENDIX

7. Astronomy Ranking Task: Stellar Evolution & Look-Back Time

Description: Imagine that the four stars listed below all became Main Sequence (MS) stars at
exactly the same time 10 billion years ago but in different locations of the universe.
A. Cosmo Star is an O spectral class star with a MS lifetime of 3 million years. Its life will
eventually end as a SN type II and become a black hole. Cosmo Star is located in a galaxy 10
billion light years (ly) from Earth.
B. Ollie Star is a K spectral class star with a MS lifetime of 30 billion years. Its life will
eventually end as a slowly cooling white dwarf. Ollie Star is located in the MW at a distance of
10,000 ly from Earth.
C. Sullivan Star is an F spectral class star that is part of a binary star system. It has a MS
lifetime of 5 billion years. Its life will eventually end in a SN type I that completely destroys
Sullivan Star. Sullivan Star is located in a galaxy 6 billion ly from Earth.
D. Sliver Star is a B spectral class star with a MS lifetime of 20 million years. Its life will
eventually end as a SN type II and become a neutron star. Sliver is located in our Milky Way
Galaxy at a distance of 40,000 ly from Earth.
(Sketch below if this is helpful)

A. Ranking Instructions Rank the stars (from first to last) based on when an observer on Earth
would see their final end states.
Ranking Order: First 1 ____ 2 ____ 3 ____ 4 ____ Last
Or, all the stars would appear in their final state at the same time. _____ (indicate with a check

mark)
Carefully explain your reasoning for ranking this way:
_____________________________________________________________________
_____________________________________________________________________

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