1. If the Moon stopped dead in its orbit around Earth, it would
   a) fall into the Earth in a few days
   b) fall into the Earth in a few weeks
   c) fall into the Earth in a few years
   d) just stay where it is, it is in orbit
   
   
2. If an object in space emits only thermal radiation, the average energy of each photon
   a) is the same for all such objects
   b) depends only on the object's temperature
   c) depends on the object's temperature and size
   d) depends on a host of other unknowns
   
   
3. The reason the solar system is in a plane is because it contains
   a) angular momentum of orbits
   b) heat and energy
   c) planets and asteroids
   d) comets and dust
   
   
4. Most of the energy that the Sun emitted while it was still forming came from
   a) gravitational contraction
   b) nuclear fusion involving hydrogen
   c) radioactive decay involving uranium
   d) chemical reactions involving oxygen
   
   
5. The main difference between what the atmospheres of Earth and Venus are made of is due to
   a) the different masses of the two planets
   b) the absence of greenhouse gases on Venus
   c) the presence of volcanoes on Venus
   d) the presence of oceans on Earth
   
   
6. Mars is about 1.4 A.U. from the Sun. Use Kepler's law and some logic to determine about how long it takes to fly there from the Earth, by tracking halfway around an elliptical orbit around the Sun.
   a) about 1.4 months
   b) about 3 months
   c) about 6 months
   d) a little over a year
   
   
7. The most common molecule in the air in your lungs right now has what important biological function?
   a) it is helping you hold up the atmosphere above you
   b) it is involved in life-giving chemistry in your body
   c) it maintains enough of a greenhouse effect to keep Earth warm
   d) it sustains photosynthesis in plants
   
   
8. The larger is an asteroid, the more likely it is to have
   a) frozen water on its surface
   b) an irregular shape
   c) a rocky core
   d) a metallic core
   
   
9. When a bug hits your windshield, the action/reaction pair force to the force that splatters the bug is
   a) the force that got the car moving so fast
   b) the force that keeps the car in contact with the road
   c) the force of the bug that very slightly slows your car
   d) there is no reaction force there, the bug is too small
   
   
10. A ruler that zooms past you at 99 percent of the speed of light
    a) only seems shorter, it's an illusion of the way it looks
    b) is actually shorter from your perspective
    c) is the same for all observers, that's why it's a ruler
    d) is only shorter if it was accelerated, not if you were
    
    
    Answers: (1-5) bbaad
    (6-10) cadcb