大気圏（たいきけん、taikiken）
- atmosphere

The Japanese word 大気圏 大気圏 (たいきけん - taikiken) refers to the atmosphere surrounding a celestial body, such as a planet or a moon. It's the layer of gases held in place by gravity that surrounds the object. The term emphasizes the boundary and the region of gases.

⚫︎地球の 大気圏 Translation: The Earth's atmosphere. ⚫︎宇宙船は 大気圏 を再突入した。 Translation: The spacecraft re-entered the atmosphere. ⚫︎火星の 大気圏 は薄い。 Translation: The Martian atmosphere is thin.

This word is used in scientific, technical, and general contexts when discussing the atmosphere of a celestial body. It is often used when talking about space exploration, the environment, or astronomy. You would use it when describing things like the composition, layers, or properties of an atmosphere.

The word is typically written in kanji and hiragana: 大気圏. The reading is たいきけん in hiragana. There are no other common ways to write this word. The okurigana is standard.

There aren't direct synonyms that replace 大気圏 completely, but related terms include: ⚫︎大気 (taiki) - atmosphere (more general) ⚫︎空気 (kuuki) - air (more general)

There aren't direct antonyms for 大気圏 as it refers to a physical space. However, concepts relating to the absence of an atmosphere would be the opposite. ⚫︎宇宙空間 (uchuu kuukan) - outer space

ロケットは 大気圏 を突破し、宇宙へ向かった。 ・Translation: The rocket broke through the atmosphere and headed into space. ・Explanation: This sentence describes the rocket’s journey out of Earth's atmosphere.

大気圏 再突入時の熱は非常に高い。 ・Translation: The heat during atmospheric re-entry is extremely high. ・Explanation: This sentence discusses the intense heat experienced when a spacecraft re-enters the atmosphere.

The word 大気圏 is a compound word. ⚫︎大気 (taiki) - atmosphere; "great air" ⚫︎圏 (ken) - sphere; realm; zone Therefore, the word literally means "atmosphere sphere/zone." It describes the area that contains the atmosphere.