Minor Members of the Solar System

Asteroids: Small Rocky Bodies

• Most asteroids lie in the asteroid belt between the orbits of Mars and Jupiter

• Their orbital periods are between 3 & 6 years

Comets: “Dirty Snowballs”

• Pieces of rocky and metallic materials held together by frozen gases (including water)• Has a small nucleus of a

few kilometers in diameter• Many develop a “tail” (or

even two tails) as they near the sun

The Sources of Comets

• Kuiper Belt: Short period comets coming from a region beyond Neptune and lie roughly in the plane of the solar system

• The Oort Cloud: Long orbital periods coming from a spherical shell far beyond Pluto

Meteoroids• Originate from one of three

sources: 1.Interplanetary debris not

swept out (yet!) by the formation of the planets

2.Material from the asteroid belt

3.The solid remains of comets that traveled near the Earth’s orbit

Meteors and Meteorites

• A meteor is a meteoroid that enters the Earth’s atmosphere and burns up

• A meteoroid that hits the surface of the Earth is a meteorite

Whiteboard Summary

1. Where among the planets are asteroids are most likely located?

2. What are the common components of a comet?

3. What is the difference between and meteor and a meteorite?