Astronomy Picture of the Day

Explanation:

肉眼可見的獵戶大星雲，是位於著名獵戶腰帶三星附近的瀰漫光斑。 上圖呈現了因反射獵戶座亮星而現身的部分獵戶大星雲。 此反射星雲的顏色之所以偏藍，則是因為星雲的氣體反射鄰近恆星藍光的效率高於反射紅光。 影像中的黝黑帶紋，其主要成分是由細針狀的碳微粒所組成的星際塵埃。

The Orion Nebula is visible to the unaided eye as a fuzzy patch near the famous belt of three stars in the constellation Orion. The above picture captures a part of the Orion Nebula that primarily reflects light from bright Orion stars. This reflection nebula appears blue because the blue light from the neighboring stars scatters more efficiently from nebula gas than does red light. The dark lanes are composed of mostly interstellar dust - fine needle-shaped carbon grains.