ASTRON C10 Lecture Notes - Lecture 15: Grilling, Kinetic Energy, Tunguska Event

• School: Berkeley
• Department: Astronomy
• Course: ASTRON C10
• Professor: Alexei Filippenko

Document Summary

Earth"s rotation is gradually slowing down owing to tidal friction: the day gets longer by about 2 seconds per 100,000 years. Moon is slowly receding from earth (4 cm per year) Earth is stretched by the moon, moon steals an angular momentum from earth"s rotation: Loss of earth"s angular momentum = increase in moon"s angular momentum. Comets come from kuiper belt and its extension ( scattered disk ) and also from the oort cloud (a sphere perhaps 10^12 comets, about 50,000 au from the sun). If they were all from the kuiper belt: all come in the same plane. Oort cloud: possible leftovers from the formation of planets. Icy bodies in and around jupiter and saturn that were flung out. Sometimes perturbed by collisions and gravitational interactions: deflected into the inner. Interest: primitive, cold material that haven"t been changed. Semimajor axis: big indicator of the period. Occupy belt at 2. 8 au from sun.