Asteroid

How to spell asteroid

8 letters · 3 syllables

How to pronounce asteroid

Say the part in capitals loudest.

What does asteroid mean?

1. nounA small rocky body that orbits the Sun, mostly found in a belt between Mars and Jupiter.

Asteroid in a sentence

• The telescope tracked a distant asteroid as it crossed the night sky.

• Scientists calculated that the asteroid would pass safely past the Earth.

Where does asteroid come from?

Language of origin: Greek

The word was assembled from Greek elements in the early 1800s: aster, meaning 'star', joined to the suffix -oeides, meaning 'having the form of' or 'resembling'. So an asteroid is literally a 'star-like' object, a name chosen because these small bodies looked like faint points of light through early telescopes, much as stars do, even though they are rocky objects orbiting the Sun. The English astronomer William Herschel is generally credited with coining the term around 1802, soon after the first of these minor planets, Ceres, was discovered. The same aster root sits inside the familiar words 'astronomy', 'astronaut', and the flower called the aster, whose petals radiate like a star. Remembering that star connection helps with the spelling: it begins aster-, not 'astro-', and the ending is the resemblance suffix -oid, as in 'humanoid' or 'spheroid'.

How the word is built

• aster- (from Greek aster: star)
• -oid (from Greek -oeides: having the form of, resembling)