November 3, 2000; Due: November 10, 2000

The Sibyl with raving mouth utters things mirthless and unadorned and unperfumed, and her voice carries through a thousand years because of the god who speaks through her.

Heraclitus, Peri Physeos, Fragment XXXIV

The Chicxulub crater was caused by a small asteroid. Use what you know about orbits to deduce some of the characteristics of asteroid orbits that would threaten the Earth (i.e. that could hit us). Discuss how often a dangerous “near miss” might occur.
Saturn is at opposition on November 19. How far will it be from Earth at that time?
In class I said that the Galilean satellites of Jupiter obeyed Kepler’s Laws, with the proviso that since the mass of Jupiter is different from that of the Sun, you cannot express a in astronomical units and P in years. Demonstrate that the orbits of the Galilean satellites do indeed obey Kepler’s third law.
Astronomy books say that the tilt of Saturn’s rotation axis with respect to the plane of the ecliptic is 26.7 degrees. Describe a way in which you could verify this using you own telescopic observations or measurements from pictures. Give details. Actually doing it is the best way of demonstrating that you understand the concept.
Why are oxygen compounds such as carbon monoxide and carbon dioxide extremely low in abundance in the atmospheres of Jupiter and Saturn?