s*****t 发帖数: 1994 | 1 A Beautiful Trifid
Credit & Copyright: Jim and Janet Castano, Adam Block, NOAO, AURA, NSF
Explanation: The beautiful Trifid Nebula (aka M20), a photogenic study in cosmic contrasts,
lies about 5,000 light-years away toward the nebula rich constellation Sagittarius. A star
forming region in the plane of our galaxy, the Trifid alone illustrates three basic types of
astronomical nebulae; red emission nebulae dominated by light from hydrogen atoms, blue
reflection nebulae produced by dust reflec |
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