All About Asteroids, Comets, and Meteors.
What is the difference between an asteroid, a comet, and a meteor? asteroid, Ceres (SEER-eez), is so big, it's actually considered a dwarf planet. or as large as a few hundred miles! At more than 500 miles wide, the largest Thousands of asteroids orbit the sun in the asteroid belt, which is a rocky ring between Mars and Jupiter. There, Jupiter's strong gravity prevents the asteroids from flying off into space. A comet-sometimes called a "dirty snowball"-is a chunk of ice and dirt. As it approaches the sun, it heats up. This creates a long "tail" of gas and dust that glows in the night sky. Like asteroids, comets orbit the sun, but the journey for some of them is very long. Halley's Comet passes by Earth about every 76 years. So mark your calendar-it will be shooting past our planet again in 2061! A meteor is a small piece of an asteroid or comet that hits Earth's atmosphere. It's usually no bigger than a pebble! You may know meteors by their nickname-"shooting stars." Now here's where it gets a little tricky. When that pebble is out in space, it is a meteoroid. When it burns up in our atmosphere, the streak of light it produces is a meteor. And if it actually crashes into Earth, it is a meteorite!
•orbit •gravity •journey •atmosphere •streak
1._______a trip
2._______the air around Earth
3._______a long, narrow line or mark
4._______ the force that pulls things toward a planet
5._______ to move around an object