The Moon

1. What causes the phases of the Moon?
A).. The shadow of the Earth on the Moon.
B)..The shadow of the Sun on the Moon.
C).. The Moon's motion around the Earth causing us to see different amounts of it lit.
D)..A dark cloud in orbit between us and the Moon.
E).. Peculiar absorption of light by the Moon's surface.

If the above question stumped you, look at the animation below.

Animation of Phases of the Moon

2. Why does the Moon shine in the sky?
A)...It's surface is so hot.
B)... It reflects light from the Earth.
C)...It reflects light from the Sun.
D)...It reflects light from the stars.
E)...Light from its core leaks out through the craters.

3. Which of the following two astronomical effects that we see on Earth are caused by the Moon?
A)... Day and night.
B)... Summer and Winter.
C)... Tides and Eclipses.
D)... Spring and Fall.
E)... Ice ages and El Nino.

Earth and Moon The figure shows the Earth and Moon to correct relative size, although not to proper distance.

4. About how big is the Moon's radius compared to the Earth's?
A) half.
B)... one quarter.
C)... one tenth.
D)... one one hundreth.
E)... one sixteenth.

5. What are the large smooth dark areas (Such as B in the figure below) called?
A)... Highlands.
B)... Rilles.
C)... Rays.
D)... Maria.
E)... Strato-vents.


The larger dark areas are ancient congealed lava that flooded into immense craters made by asteroids when the Moon was young. The simple animation below shows what astronomers think may have happened. Movie of formation of Mare Serenitatis

6. Given that the Moon's diamter is about 3500 km ( roughly 2000 miles), about how big across is the dark area marked B?
A)... 180 km.
B)... 38 km.
C)... 580 km.
D)... 58 km.
E)... 1380 km.

7. What are the smaller round pits with raised rims (such as you can see in the Figure) called?
A)... Craters.
B)... Rilles.
C)... Rays.
D)... Roche rings.
E)... Millipores.

8. What created the white streaks that you can see radiating from the point C?
A)... A volcanic eruption.
B)... Wind blowing dust in the lunar atmosphere.
C)...Material "splashed" out by the impact of a large object.
D)... A very intense local magnetic field that aligned the lunar surface dust.
E)... Water flowing out of a pit as the Sun warms and melts sub-surface ice.

9. Why don't you see any signs of clouds or haze above the Moon's surface?
A)... The molecules are are too small.
B)... The Moon has no atmosphere.
C)... The Sun shines directly down so it does not reflect strongly.
D)...The Moon is so hot that clouds and haze can't condense.
E)... Microbes in the Moon's atmosphere "eat" all the particles that condense there.

10.Why doesn't the Moon have an atmosphere?
A)... It is so cold that all the gases have frozen out and are buried below the surface.
B)... It spins so fast that all the gases have been flung off into space long ago.
C)... It is not massive enough to have a strong enough gravitational pull to hold onto gases.
D)... The question is a trick. The Moon has a dense atmosphere..
E)... The Moon's atmosphere is all on the dark side that we can't see from Earth.

11. What causes tides?
A)... The Moon's gravity.
B)... The Moon's magnetic field.
C)... The Moon's magnetic field.
D)... The elliptical shape of the Moon's orbit.
E)... The elliptical shape of the Earth's orbit.

The short movie below shows how the Moon's gravity pulls harder on the near side water than on the far-side water and creates the two bulges that lead to the tides.

Animation of Tides

12. What is the Moon's phase at a lunar eclipse?
A)... New.
B)... Full.
C)... First Quarter.
D)...Third quarter.
E)... It can be any phase; it depends..

Animation of Total Lunar Eclipse

13. How are the Moon and eclipses related?
A)... The Moon's shadow falls on the Earth at a solar eclipse.
B)... Earth blocks sunlight from reaching the Moon at a lunar eclipse.
C)... The Moon's gravity bends light away from the Earth at a solar eclipse.
D)... Both A and B.
E)... None of the above.

14. We don't get eclipses every month. This is because
A)... the Moon has phases.
B)... the Earth's rotation axis is tilted with respect to its orbit.
C)... the Moon's orbit is tilted with respect to the Earth's orbit.
D)... the Earth's orbit is elliptical.
E)... the Moon's orbit is elliptical.

Your Answers
Your answer to the question was