Asteroid (noun)

1. A small rocky body that orbits the sun, typically smaller than a planet and without an atmosphere.
2. A celestial object, similar to a comet, that is in orbit around the sun.

Origin:

Early 19th century: from greek asteroeidēs "starlike", from aster "star" + -oeidēs "-like".

Examples:

1. NASA's mission to explore the asteroid belt was a success.
2. Scientists are studying the asteroid to learn more about the early solar system.
3. Asteroids have been known to collide with planets, including Earth.
4. Many asteroids have been discovered to have their own moons.
5. The asteroid was captured by the gravity of Jupiter and became a Trojan asteroid.