土星、土卫六、土星环与烟霾
影像来源与版权:NASA, ESA, JPL, SSI, Cassini Imaging Team

说明:这不是日食。以上这幅影像呈现了土星卫星和土星环的热闹景象。影像中央的庞大圆形天体是土卫六,它是土星最大的卫星,也是整个太阳系中最引人注目的天体之一。土卫六中央的黑点是其固体核心,它周围明亮的光环是土卫六外层的大气烟霾。这种气体散射太阳光,以致装载在卡西尼号宇宙飞船上的相机能够捕捉到它。横切过这幅影像的是几乎侧视的土星环。土卫六右下方的黑点是土星的一颗小卫星土卫二。由于这幅影像几乎是对着太阳拍摄的,土卫六和土卫二的表面呈现出剪影,土星环则看起来像一张照相底片。现在,如果你非常仔细地观察土卫二,你可以看到一些正向影像底部喷发的冰冷喷流。这些冰冷喷流激发了人们未来登陆土卫二、探索冰层以及寻找外星生命迹象的计划。
翻译:北京天文馆

Saturn, Titan, Rings, and Haze
Image Credit & Copyright: NASA, ESA, JPL, SSI, Cassini Imaging Team

Explanation: This is not a solar eclipse. Pictured here is a busy vista of moons and rings taken at Saturn. The large circular object in the center of the image is Titan, the largest moon of Saturn and one of the most intriguing objects in the entire Solar System. The dark spot in the center is the main solid part of the moon. The bright surrounding ring is atmospheric haze above Titan, gas that is scattering sunlight to a camera operating onboard the robotic Cassini spacecraft. Cutting horizontally across the image are the rings of Saturn, seen nearly edge on. At the lower right of Titan is Enceladus, a small moon of Saturn. Since the image was taken pointing nearly at the Sun, the surfaces of Titan and Enceladus appear in silhouette, and the rings of Saturn appear similar to a photographic negative. Now if you look really really closely at Enceladus, you can see a hint of icy jets shooting out toward the bottom of the image. It is these jets that inspired future proposals to land on Enceladus, burrow into the ice, and search for signs of extraterrestrial life.
Astronomy Picture of the Day 05/05/2019