- The definition of an asteroid is a rocky mass that orbits the sun.
Facts About Astroids
- More than 1,800 asteroids have been identifed in the solar system.
- Asteroids are made from one of three types of materials:
- C-type - Made of carbon containing rocks
- S-type - Made of silicon-based rocks
- M-types - Large asteroids which contain metal
- Scientists believe that asteroids may be the remains of the formation of the solar system - the Big Bang explosion. The material that was not pulled into one of the planets remained in space and began its own cooling process. The material that did not get pulled into a planetary gravitational field continues to grow as an asteroid.
- The most common source of asteroids is the main asteroid belt between Mars and Jupiter.
- The largest asteroid on record is Ceres which is large enough to be considered a dwarf planet, amounting to approximately 27% of the total mass of the main belt of asteroids that lie between Mars and Jupiter.
A small planet whose orbit is between Mars and Jupiter is an example of an asteroid.
A ring of asteroidsLicensed from iStockPhoto
Origin: Classical Greek asteroeidēs ; from astēr, star plush eidēs, -oid
- any of the thousands of small planets ranging from 1,000 km (621 mi) to less than one km (0.62 mi) in diameter, with orbits usually between those of Mars and Jupiter; minor planet; planetoid
- Zool. starfish
Used by arrangement with John Wiley & Sons, Inc.
- Astronomy Any of numerous small celestial bodies that revolve around the sun, with orbits lying chiefly between Mars and Jupiter and characteristic diameters between a few and several hundred kilometers. Also called minor planet, planetoid.
- Zoology See starfish.
Origin: From Greek asteroeidēs, starlike : astēr, star; see ster-3 in Indo-European roots + -oeidēs, -oid.
asteroid - Cultural Definition
asteroid - Science Definition
Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.