Translation guide
An asteroid is a small rocky body orbiting the sun. In Japanese, the standard term is 小惑星 (shōwakusei). In casual or sci-fi contexts, アステロイド (asuteroido) is also used.
Referring to a rocky object in space, smaller than a planet, orbiting the sun.
小惑星 is the formal, scientific term used in news and textbooks. アステロイド is a loanword often heard in pop culture, games, and casual talk. Use 小惑星 in most contexts.
Standard scientific and general term for asteroid.
An asteroid is approaching Earth.
This asteroid is about 500 meters in diameter.
Loanword from English, used in casual conversation, games, or sci-fi. Less formal than 小惑星.
I like games where you destroy asteroids.
Literally 'stardust', sometimes used poetically for small celestial bodies like asteroids or meteoroids. Not a scientific term.
Countless asteroids drift in space.