Small Space Objects

1. Small Space Objects

2. Objects in the Solar System • The materials in a space body depend on where it formed • The disk of material that became the solar system was cold around the outside and hottest in the center, where the Sun was forming

3. Objects in the Solar System • Bodies that formed near the center of the solar system are made mostly of rock and metal • Bodies that formed far from the center are mostly ice with some rock and a little metal

4. Pluto and Charon • Because Pluto and Charon (Pluto’s moon) orbit each other, they are sometimes called a double planet

5. Pluto and Charon • Pluto’s path around the Sun is not as round as the orbits of the rest of the planets, so its distance from the Sun changes a lot as it orbits • Pluto’s orbit is tilted compared to those of the other planets

6. Asteroids and Comets Orbit the Sun • Objects called asteroids and comets formed along with the Sun, planets, and moons • The objects still orbit the Sun at different distances • Most of the objects are much smaller than planets and have too little mass to be become round

7. Asteroids • Asteroids – small, solid, rocky bodies that orbit close to the Sun • Most asteroids have irregular shapes

8. Asteroids • Most asteroids have paths that keep them between the orbits of Mars and Jupiter – this huge region is called the asteroid belt, and contains more than 10,000 asteroids • The surfaces of asteroids are covered with craters, broken rock, and dust

9. Comets • Comet – an object that produces a coma • A comet without its coma is a small, icy object that is difficult to see even with a powerful telescope

10. Comets • Comets are made of different ices as well as rock and some metal • Their orbits are usually more oval than the paths of planets

11. Comets • When a comet gets close to the Sun, solar radiation warms the surface and turns some of the ice into gas – a coma forms as the gas moves outward, often carrying dust with it, pushing this material into one or more tails • A comet’s tails point away from the Sun no matter which way the comet is moving

12. Meteors and Meteorites • Particles in space and the air around them become hot enough to glow, producing brief streaks of light called meteors • Meteor showers occur when Earth passes through a stream of orbiting particles left by a comet

13. Meteors and Meteorites • Meteorite – a space object that reaches Earth’s surface • Most meteorites come from the asteroid belt