2017年11月29日:M42：猎户座大星云-（M42: The Great Orion Nebula） 2017年11月29日:M42：猎户座大星云-（M42: The Great Orion Nebula）--原图下载{mtitle title="M42：猎户座大星云"/}Image Credit & Copyright: Francesco Battistella说明: 鲜少有天文景观能像着名的猎户座星云，这个邻近的恒星育婴室这么善于激发着人们的想像。这个星云的辉光云气，环拱着位在一个庞大星际分子云里的炽热年轻恒星。而在这幅主题影像里的许多丝状云气结构，事实上是激波前沿，在该处，高速移动的物质遇到慢速移动的气体。跨幅约40光年、距离约1,500光年的猎户座大星云，和太阳都位在银河系的同一道旋臂上。座落在着名猎户座内、轻易可辨的腰带三星左下方之猎户座大星云，是个肉眼可见天体。上面这幅主题照片，是在上个月使用2小时长曝光拍摄的三色影像。包括马头星云在内的整个猎户座星云複合体，在接下来的100,000年之内，会慢慢的散开来。{lamp/}原文：{mtitle title="M42: The Great Orion Nebula"/}Image Credit & Copyright: Francesco BattistellaExplanation: Few astronomical sights excite the imagination like the nearby stellar nursery known as the Orion Nebula. The Nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud. Many of the filamentary structures visible in the featured image are actually shock waves - fronts where fast moving material encounters slow moving gas. The Orion Nebula spans about 40 light years and is located about 1500 light years away in the same spiral arm of our Galaxy as the Sun. The Great Nebula in Orion can be found with the unaided eye just below and to the left of the easily identifiable belt of three stars in the popular constellation Orion. The featured image, taken last month, shows a two-hour exposure of the nebula in three colors.The whole Orion Nebula cloud complex, which includes the Horsehead Nebula, will slowly disperse over the next 100,000 years.