Homework MUST be neat, meaning typed, word-processed, or very neatly hand written. We must be able to read and understand your homework for you to receive full credit. SHOW your calculations on any problems and JUSTIFY written answers - `yes' or `no' is not adequate. Do NOT COPY from the book or the Web. This is plagiarism and violates the University honor code. Though readings in the book may be the basis of your answer, it is important to phrase all answers in your own words. Do NOT COPY from a fellow student. This is academic dishonesty. You may discuss homework with friends, but the final product must be your own work.

If you make use of references other than the textbooks or class handouts, include the reference information (book title & author; WWW URLs) at the end of your assignment. The University's honor code will be enforced. See page 36 of the Schedule of Classes.

Homework 1 Questions:

1. Comets:
   Describe the orbit of a typical comet. Relatively speaking, how much time does it spend near to and far from the sun? What happens as a comet nears the sun that sometimes makes it visible?

2. Observed Crater Densities:
   Satellites (moons) and planets with solid surfaces show great variation in the number of craters that are visible. Describe the processes which can modify a surface which started out with many craters when the solar system was young (4 billion years ago).

3. Make use of the WWW tool Astronomical Distances to answer the following questions:
   • a) How long would it take you to reach the Moon if you traveled in a spaceship as fast as a car? As fast as a commercial airliner? Choose typical values for these speeds. If you are unsure of typical speeds, ask someone!
   • b) How many times further away is Pluto than our Moon? How many times further away is Proxima Centauri than Pluto? How many times further away is the center of the Milky Way than Proxima Centauri? (HINT: how is the ratio of travel times related to the desired ratios of distances?)
   • c) A club popular with all space faring species in the galaxy is Joe's Canteen and Deuterium Depot, conveniently located at the center of the Milky Way. Joe's is particularly noted for its delectable FAF (Flaming Arcturian Flamingo). Alas, the Arcturian Flamingo has been placed on the Galactic Endangered Species List. This news will reach Joe's in 25,000 years, where there will no doubt be one last great multi-species interstellar feast. If you leave Earth now and make the best possible speed, can you make it in time to eat FAF at Joe's?
     Why or why not?