马头星云
2019 October 6 The Horsehead Nebula Image Credit & Copyright: José Jiménez Priego Explanation: The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the red emission nebula in the center of the above photograph. The horse-head feature is dark because it is really an opaque dust cloud that lies in fron...