comets and asteroids

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Comets	Asteroids
Made up of ice and dust	Made up of rocks and metals
Form tails when they pass through the inner solar system	Do not form tails
Typically have orbits that are very much more elliptical and tilted than those of the planets	Typically have orbits that are more elliptical and tilted than those of the planets
Usually orbit the Sun in two regions: the Kuiper belt (about 30 to 100 AU from the Sun) and the Oort Cloud (extending out to about 50,000 AU from the Sun)	Usually orbit the Sun in the asteroid belt, a region between Mars and Jupiter
Typically remain in the outermost regions of the solar system (beyond the orbit of Neptune), but can pass through the inner solar system if their orbits are elliptical enough	Typically remain in the asteroid belt, a region between Mars and Jupiter
May or may not orbit the Sun in the same direction as the planets	Orbit the Sun in the same direction as the planets
Usually undetectable to the naked eye; may become visible while passing through the inner solar system	Virtually undetectable to the naked eye
Meteor showers usually occur when Earth passes through a stream of particles left behind by a comet in its orbit	Produce meteors (streaks of light) upon entering Earth’s atmosphere; produce meteorites if they (either whole or in part) survive the trip through Earth’s atmosphere and hit the ground