For some of the questions you will need to use outside/internet resources to find the relevant information.

1. Kepler's third law sets the relative size of the solar system as it defines a relation between orbital period (as measured in earth years) and orbital distance (as measured in AUs). One AU = one astronomical unit = the distance from the earth to the Sun. Using Kepler's third law, answer the following questions.

   a) What is the orbital period of an object at distance of 4 AU from the Sun?

   b) What is the orbital period of an abject at a distance of 100 AU from the Sun?

   c) What is the distance to an object which has an orbital period of 36 years?

2. Assume that the orbit of the Earth around the Sun is perfectly circular with a radius of 150 million kilometers. The orbital period of course is one year. From this information, compute the orbital velocity of the earth about the Sun, in units of kilometers per second. Show your work.
3. Dawn is the name of a recently launched NASA Mission. Summarize the science goals of Dawn and explain why this mission is fairly unique.
   
   
4. Summarize some of the evidence for the existence of volcanoes on the surface of Venus and explain how new discoveries by the European Space Agency's mission, The Venus Express, suggest that Venus and the Earth may be more similar than previously thought.
   
   
5. How do crater counts on the surfaces of objects in our solar system help to determine the age of that surface? How do we know that there were two distinct cratering epochs on the Moon?