How to say "asteroid" in Japanese

• 小惑星しょうわくせいCommon
  nounThe common word for the astronomical sense: a small rocky body orbiting in space. If you mean the space object that 'asteroid' normally refers to, this is the word to reach for.
• ひとで
  nounCovers 'asteroid' only in the zoological sense, an echinoderm of the class Asteroidea — in ordinary use it just means starfish. It is usually written in kana and never means the space object.
• アステロイド
  nounThe katakana rendering of 'asteroid', pointing to the same astronomical sense as 小惑星. As a less common loanword, it is seldom the word you want; choose 小惑星 for the space rock.

Use 小惑星 for the astronomical 'asteroid', the small body in space; 「ひとで」 only for the zoological sense, a starfish of the class Asteroidea; 「アステロイド」 is a less common loanword for the space rock.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 小惑星しょうわくせいasteroid
• ひとでstarfish
• アステロイドasteroid