asteroid
[as-tuh-roid]
- Also called minor planet. Astronomy. any of the thousands of small bodies of from 480 miles (775 km) to less than one mile (1.6 km) in diameter that revolve about the sun in orbits lying mostly between those of Mars and Jupiter.
- Zoology. an asteroidean; a starfish.
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Origin of asteroid
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Related Words
sphere, earth, globe, world, asteroid, marble, orb, apple, planetoid, moon, rocket, spacecraft, luna, sputnik, terrene, ancillaryExamples from the Web for asteroid
Contemporary Examples
What would it take to carry people to the Moon, or Mars, or an asteroid?
Thinking of longer journeys to Mars or an asteroid would require careful measurement of conditions.
His game lasts until his final ship has either collided with an asteroid or lost a shootout with an enemy saucer.
The Asteroid Belt in the Solar System has many such gaps, created by the gravity of the Sun and Jupiter.
For the record, Deep Impact is about a comet, not an asteroid.
U.S.—Russia Tensions Nuke Plans For Real-Life ‘Armageddon’ Asteroid DefenseAsawin Suebsaeng
August 4, 2014
Historical Examples
But the mechanism controlling the asteroid's invisibility was not destroyed.
The Bluff of the HawkAnthony Gilmore
The first was never heard of after thirty-six hours on the asteroid.
The Planetoid of PerilPaul Ernst
Anything that kept them from selling an asteroid must be terrible indeed.
The Planetoid of PerilPaul Ernst
The asteroid was too tiny to give him indefinite concealment.
The Planetoid of PerilPaul Ernst
For an instant there was a silence in the darkness of the asteroid that was painful.
The Planetoid of PerilPaul Ernst
asteroid
- Also called: minor planet, planetoid any of numerous small celestial bodies that move around the sun mainly between the orbits of Mars and Jupiter. Their diameters range from 930 kilometres (Ceres) to less than one kilometre
- Also called: asteroidean (ˌæstəˈrɔɪdɪən) any echinoderm of the class Asteroidea; a starfish
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- of, relating to, or belonging to the class Asteroidea
- shaped like a star
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Word Origin
C19: from Greek asteroeidēs starlike, from astēr a star
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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Word Origin and History for asteroid
Online Etymology Dictionary, © 2010 Douglas Harper
asteroid
[ăs′tə-roid′]
- Any of numerous small solar system bodies that orbit the Sun primarily in the asteroid belt, a region between the orbits of Mars and Jupiter. Asteroids are intermediate in size between planets and meteoroids with diameters that measure between approximately one hundred and several hundred kilometers. While more than 1,800 asteroids have been cataloged, and as many as a million or more smaller ones may exist, their total mass has been estimated to be less than three percent of the Moon's. Asteroids are thought to be left over from the early formation of the solar system, when planetesimals in a protoplanetary disk were scattered after coming under Jupiter's gravitational influence. The continuing collision of planetesimals that remained between Jupiter and Mars caused many of them to fragment, creating the asteroids that exist today. Also called minor planet planetoid
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The American Heritage® Science Dictionary
Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
asteroid
[(as-tuh-royd)]
A small planet that revolves around the sun. The largest asteroid is only about six hundred miles in diameter. (See asteroid belt.)
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The New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.