ASTEROID

asteroid, star-shaped

(adjective) shaped like a star

asteroid

(noun) any of numerous small celestial bodies composed of rock and metal that move around the sun (mainly between the orbits of Mars and Jupiter)

Source: WordNet® 3.1


Etymology 1

Noun

asteroid (plural asteroids)

(zoology) Any member of the taxonomic class Asteroidea; a starfish

Etymology 2

Noun

asteroid (plural asteroids)

(astronomy) A naturally occurring solid object, which is smaller than a planet and is not a comet, that orbits a star

(astronomy) In the Solar system, such a body that orbits within the orbit of Jupiter

Usage notes

The term "asteroid" has never been precisely defined. It was coined for objects which looked like stars in a telescope but moved like planets. These were known from the asteroid belt between Mars and Jupiter, and were later found co-orbiting with Jupiter (Trojan asteroids) and within the orbit of Mars. They were naturally distinguished from comets, which did not look at all starlike. Starting in the 1970s, small non-cometary bodies were found outside the orbit of Jupiter, and usage became divided as to whether to call these "asteroids" as well. Some astronomers restrict the term "asteroid" to rocky or rocky-icy bodies with orbits up to Jupiter. They may retain the term planetoid for all small bodies, and thus tend to use it for icy or rocky-icy bodies beyond Jupiter, or may use dedicated words such as centaurs, Kuiper belt objects, transneptunian objects, etc. for the latter. Other astronomers use "asteroid" for all non-cometary bodies smaller than a planet, even large ones such as Sedna and (occasionally) Pluto. However, the distinction between asteroid and comet is an artificial one; many outer "asteroids" would become comets if they ventured nearer the Sun. The IAU terminology since 2006 has been small Solar System body for any body that orbits the Sun directly and whose shape is not dominated by gravity.

Anagrams

• ideators

Source: Wiktionary


As"ter*oid, n. Etym: [Gr. astéroïde. See Aster.]

Definition: A starlike body; esp. one of the numerous small planets whose orbits lie between those of Mars and Jupiter; -- called also planetoids and minor planets.

Source: Webster’s Unabridged Dictionary 1913 Edition



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Word of the Day

27 April 2024

GREAT

(adjective) remarkable or out of the ordinary in degree or magnitude or effect; “a great crisis”; “had a great stake in the outcome”


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Coffee Trivia

Plain brewed coffee contains almost no calories, while coffee with dairy products, sugar, and other flavorings is much higher in calories. An espresso has 20 calories. A nonfat latte has 72, while a flavored one has 134.

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