Message #194037

[Atrion]

WHAT ARE ASTEROIDS? Asteroids are not the same as comets. Comets are essentially large, dirty snowballs. They are made of ice and frozen gases, mixed with rocky material and dust, and travel in large oval orbits, sometimes leaving our solar system. In contrast, asteroids are metallic, rocky bodies, without atmospheres, that orbit the Sun, just like planets, but are too small to be considered planets themselves. There are tens of thousands of them gathered into the main asteroid belt, a donut-shaped ring located between the orbits of Mars and Jupiter. Astronomers conclude they are made from primordial rock. Jupiter's strong gravity prevented these small bodies from forming into a planet when the solar system began 4.6 billion years ago.