Use these questions to test your understanding. If you get them wrong, you will be linked back to the relevant part of the notes. 

Be sure you study them thoroughly (don't just get a quick fix for your mistake) so your overall understanding is improved.

1. Craters are caused by

    a. objects crashing into a planet's surface

    b. erosion

    c. bubbles rising from a planet's interior

    d. magnetic fields

    e. liquid surfaces

2. What is the main reason Mercury is hotter than the Moon?

        a. Mercury has a slower rotation rate                              b. Mercury is closer to the Sun

        c. Mercury absorbs sunlight better than the Moon          d. Mercury has more greenhouse gases than the Moon

3. The approximate age of the Solar System is

        a. 4500 years                     b. 4.5 billion years         c. 4.5 million years                 d. 10,000 years

        e. we do not know the age

4. A rock sample is analyzed and found to have only 25% as much of a radioactive element as it would have been predicted to contain originally. The half-life of the radioactive element is 8x10⁸ years. How old is this rock?

        a. 8x10⁸ years                 b. 1.6x10⁹ years         c. 2x10⁸ years             d. 3.2x10⁹ years

        e. cannot be computed from the information given

5. The lack of an atmosphere on the moon implies that

        a. it never had one             b. it escaped because of the moon's weak gravity

        c. it froze on the surface      d. it got ejected during crater formation

        e. the moon could never have been part of the earth

6. An object with no atmosphere or erosion processes is found in the Solar System with fewer craters on its surface than the lunar highlands. This object

a. has had a new layer deposited on its surface since it formed

b. has a surface as old as any in the Solar System

c. has a surface made of rock

d. has a surface made of ice

e. has surface about which no conclusions can be drawn

7. Mercury's surface looks a lot like

        a. the surface of Jupiter              b. the surface of Mars        c. the surface of the moon             d. the surface of the earth

        e. like no surface in the Solar System

8. Observations of the Moon show that the lunar maria have only 3% as many craters as the lunar highlands. It can be reasoned that

        a. lunar lava flowed across the surface BEFORE most of the Moon's larger craters were created

        b. the lunar maria must be about 4.6 billion years old

        c. comets have collided with the Moon more often than with Earth

        d. lunar lava flowed across the surface AFTER most of the Moon's larger craters were created.

9. The composition of the moon is

    a. like that of the sun

    b. like that of a white dwarf

    c. like that of Jupiter

    d. like the core of the earth

    e. similar to the earth's crust