ASTR 101 Lecture Notes - Lecture 32: Oort Cloud, Kuiper Belt, Retrograde And Prograde Motion

• School: Queen's University
• Department: Physics, Engineering Physics and Astronomy
• Course: ASTR 101
• Professor: David Alan Hanes

Document Summary

Lecture 32 - leftovers: comets, meteors and asteroids. Comet comes form latin work that means wearing long hair". Early interpretations were that aristotle thought gases rising up in to atmosphere and igniting, chinese thought celestial omens in the heavens; signi ed the death of kings. Comet becomes bright because frozen material evaporates outward from the nucleus. Head of comet is called coma; inside is nucleus. Huge coma; larger than earth and bit tail; re ect a lot of sunlight. Gas is also uoresces; absorbing energetic solar uv radiation and emitting in the visible. Sometimes have two tails, one made from ions and other made from dust particles. Tail that consists ions (charged particles); low-mass, readily pushed straight out directly away from the sun at high speed. Tail made from pebbles are more massive and move more slowly. When comet passes sun, icy material evaporates and becomes lost in space. Eventually all icy materials are gone and only pebbles are left.