Definition of asteroid

Short definition: The word asteroid means a rocky body moving through space around the sun, usually much smaller than a planet, and often discussed when talking about space science, impacts, or the early history of the solar system.

Looking for a clear and natural explanation of the word asteroid? The word asteroid is commonly used in astronomy, science news, and space discussions. It refers to small rocky objects that orbit the sun, mostly found between Mars and Jupiter. Sometimes the word also appears in news stories about space exploration or potential impacts with Earth. Below, each meaning is explained in a calm and natural way, with enough detail to feel clear, human, and informative.

Forms: asteroid, asteroids
Related: meteor n., comet n., orbit n.
Syllable: as-ter-oid

1. (Noun) A small rocky object that orbits the sun mostly found between Mars and Jupiter.

   An asteroid is a rocky body in space that travels around the sun, usually much smaller than a planet, and is commonly located in the asteroid belt between Mars and Jupiter, where millions of such objects move in stable paths.

   Scientists tracked the asteroid carefully as it passed through the inner part of the solar system without posing any danger to Earth.
   Most asteroids remain in the asteroid belt, quietly orbiting the sun for millions of years.
   Space missions have collected data from asteroids to better understand how the solar system formed.

   Synonyms: space rock, minor planet, rocky body, solar system debris, small celestial body, orbiting rock, asteroid belt object, rocky space object, planetary fragment, space object, celestial fragment, solar orbit rock
   Antonyms: planet, star, moon, large celestial body, sun, gas giant, major planet, luminous star, massive body, stellar object, central star, planetary system center

2. (Noun) An object that can pose a potential impact risk to Earth in rare cases.

   In news and scientific discussions, an asteroid may refer to a space object whose orbit comes close to Earth, drawing attention because of the possibility, however small, of collision and the need for monitoring.

   The agency announced that the asteroid would pass safely by Earth with no chance of impact.
   Astronomers constantly monitor near Earth asteroids to detect any changes in their paths.
   Movies often exaggerate the danger of an asteroid hitting Earth to create dramatic tension.

   Synonyms: near Earth object, space hazard, potential impact object, monitored space rock, close passing asteroid, tracked celestial object, near miss object, orbital threat, space risk object, monitored asteroid, approaching body, celestial risk
   Antonyms: harmless object, distant star, stable planet, fixed orbit body, non threatening object, safe celestial body, predictable planet, non approaching object, stable star, stationary reference, distant galaxy, fixed system