蛾眉相的土星

2020年8月8日

Crescent Saturn
Image Credit: NASA, ESA, SSI, Cassini Imaging Team

Explanation: From Earth, Saturn never shows a crescent phase. But when viewed from a spacecraft the majestic giant planet can show just a sunlit slice. This image of crescent Saturn in natural color was taken by the robotic Cassini spacecraft in 2007. It captures Saturn’s rings from the side of the ring plane opposite the Sun — the unilluminated side — another vista not visible from Earth. Visible are subtle colors of cloud bands, the complex shadows of the rings on the planet, and the shadow of the planet on the rings. The moons Mimas, at 2 o’clock, and Janus 4 o’clock, can be seen as specks of light, but the real challenge is to find Pandora (8 o’clock). From Earth, Saturn’s disk is nearly full now and opposite the Sun. Along with bright fellow giant planet Jupiter it rises in the early evening.

Tomorrow’s picture: elementree

蛾眉相的土星
影像提供: NASA, ESA, SSI, Cassini Imaging Team

说明: 从地球上看出去，不可能见到蛾眉相的土星。然而，从土星的后方往外看，这颗巨行星倒是可以拥有我们不熟悉的银月样貌。上面这张自然色泽的蛾眉相土星影像，是在2007年由卡西尼号太空船所拍摄。影像记录了在背阳环面见到的壮丽土星环，而这是另一个地球不得见的景观。影像的其他美丽奇景，还包括色泽曼妙的云带、环系投射在土星上的暗影、与及映在环系上的土星影子。细心的人不难找到2点钟方向的土卫一及4点钟方向的土卫十，但真正有挑战性的，则是8点钟方向的土卫十七。目前在地球的天空中，位在冲附近接近满相的土星和另一颗巨行星─木星，在入夜后即升起。

明日的图片: elementree