AST 2002 Lecture Notes - Lecture 9: Comet, Gas Giant, Kuiper Belt
Document Summary
There are 150,00 listed in catalogs and probably over a million with diameter >1km. Small asteroids are more common than large asteroids. All the asteroids in the solar system would add up to even a small terrestrial planet. Most asteroids orbit in a belt between mars and jupiter. Asteroids in orbital resonance with jupiter experience periodic nudges. Eventually those nudges move asteroids out of resonant orbits, leaving gaps in the belt. Rocky planetestimals between mars and jupiter did not accrete into a planet. Jupiter"s gravity, through influence resonances, stirs up asteroid orbits and prevented their accretion to a planet. Meteorite: a rock from space that falls through earth"s atmosphere. Meteor : the bright trail left by a meteorite. Two types: primitive: unchanged in composition since they first formed 4. 6 billion years ago. Processed: younger, have experienced process such as volcanism or differentiation. A few meteorites arrive on earth from the moon and mars.
