Astronomy Picture of the Day——连续55个夜晚的土星
55 Nights with Saturn
Image Credit & Copyright: Tunc Tezel
Explanation: For 55 consecutive nights Mediterraneanskies were at least partly clear this summer, from the 1st of July to the 24th of August 2018. An exposure from each night was incorporated in this compositedtelephoto and telescopic image to follow bright planet Saturn as it wanderedthrough the generous evening skies. Through August, the outer planet's seasonalapparent retrograde motion slowed and drifted to the right, framed by a starrybackground. That brought it near the line-of-sight to the central Milky Way,and the beautiful Lagoon (M8) and Trifid (M20) nebulae. Of course Saturn'slargest moon Titan was also along for the ride. Swinging around the gas giantin a 16 day long orbit, Titan's resulting wave-like motion is easier to spotwhen the almost-too-bright Saturn is digitally edited from the scene.
连续55个夜晚的土星
从2018年7月1日到8月24日，连续55个夜晚，地中海的夏日夜空都至少是部分晴朗的。明亮的土星漫步在这广阔的夜空之中，这是连续55个夜晚所曝光的图像与远摄和望远镜影像合成的结果。在整个八月，这颗远日行星季节性的逆行运动开始明显减缓，并且向图像右侧移动。沿着土星的移动轨迹，我们的视线接近了银河系的中央以及美丽的礁湖星云和三叶星云。土星最大的卫星土卫六（泰坦）自然追随着土星的脚步。土卫六每16天围绕这颗气态行星公转一圈。当明亮的土星通过数字处理后，土卫六像波浪一样的运动轨迹就很容易被发现了。
参考文献：
https://apod.nasa.gov/apod/image/1809/Saturn2018hd.jpg
近期文章：
Astronomy Picture of the Day——流星划过星系