How to say "comet" in Japanese

• 彗星すいせいCommon
  nounThe common, default word for a comet — the icy body that develops a glowing tail as it approaches the sun. It fits both scientific writing and everyday conversation.
  そういう方法ほうほうで彼かれはその彗星すいせいを発見はっけんしたのです。↗

  That's how he discovered the comet.
• コメット
  nounThe katakana loanword for 'comet'; it refers to the same object as 彗星 but is less common, so in ordinary sentences about the night sky 彗星 is usually the better pick.
• ほうき星ほうきぼし
  nounA poetic alternative, literally 'broom star', that pictures the comet's tail as a broom. It means the same object as 彗星 but is less common, suiting lyrical descriptions of the night sky.
• 赤気せっき
  nounA rare, marginal name for a comet — literally 'red vapor' — found in literary or historical writing. For ordinary use this is seldom the word you want.

Choose 彗星 for any comet in science or daily talk; 「コメット」 is the less common katakana loanword; 「ほうき星」 is a poetic 'broom star' name; 赤気 is a marginal literary term you will seldom need.

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

• 彗星すいせいcomet
• コメットcomet
• ほうき星ほうきぼしcomet
• 赤気せっきcomet