Description: 當彗星接近太陽時，冰質彗核中的部分固體物質會變成氣體。這些氣體主要是水蒸氣，但也會含有其他化學物質，如一氧化碳、二氧化碳、氨、甲烷和甲醇。這些氣體和塵埃粒子一起環繞著彗核，像一團模糊的球形雲，這就是彗星大氣，或稱彗發。隨著彗星越來越接近太陽，越來越多的分子在太陽的紫外線光子作用下裂解，加熱彗發，使其外部區域膨脹。最終，彗發的外部區域被電離，並形成彗星的離子尾。

Related Terms:

• 彗星
• 彗核
• 彗尾

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

This is an automated transliteration of the simplified Chinese translation of this term

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