On July 19, 2013, in an event celebrated the world over, NASA’s Cassini spacecraft slipped into Saturn’s shadow and turned to image the planet, seven of its moons, its inner rings, and, in the background, our home planet, Earth.
NASA/JPL-Caltech/SSI
On July 19, 2013, NASA’s Cassini spacecraft had a rare opportunity to image Saturn and, far in the background, Earth. This image spans about 404,880 miles (651,591 kilometers) across.
With the Sun’s powerful and potentially damaging rays eclipsed by Saturn itself, Cassini’s onboard cameras were able to take advantage of this unique viewing geometry. They acquired a panoramic mosaic of the Saturn system that allows scientists to see details in the rings and throughout the system as they are backlit by the sun. This mosaic is special as it marks the third time our home planet was imaged from the outer solar system; the second time it was imaged by Cassini from Saturn’s orbit; and the first time ever that inhabitants of Earth were made aware in advance that their photo would be taken from such a great distance.
Before the mission ended in 2017, Cassini was already a powerful influence on future exploration. Lessons learned during Cassini’s mission are being applied in NASA’s Europa Clipper mission. The mission uses an orbital tour design derived from the way Cassini explored Saturn. Launched in 2024, Europa Clipper will reach Jupiter in April 2030 and make dozens of flybys of the planet’s icy moon to determine whether there are places below the surface that could support life.
Learn more about this unique image.
Image credit: NASA/JPL-Caltech/SSI
2013年7月19日，在一次全球共庆的壮丽事件中，美国国家航空航天局（NASA）的卡西尼号探测器滑入土星的阴影之中，转身拍摄下这颗巨行星、其七颗卫星、内部环系，以及远在背景中的我们家园——地球的照片。
NASA/JPL-Caltech/SSI
这张照片横跨约404,880英里（651,591公里），记录下了卡西尼号在2013年7月19日拍摄土星及远方地球的珍贵瞬间。
由于土星本体遮蔽了太阳强烈且可能损害设备的光线，卡西尼号得以充分利用这次罕见的拍摄角度，获取了一幅全景拼接图像，展现出土星系统在阳光逆光下的细节，包括其光环系统的结构。这幅拼接图像意义非凡——它是人类第三次从太阳系外缘拍摄地球的照片，是卡西尼号第二次从土星轨道捕捉地球影像，更是历史上第一次人类在照片拍摄前就知道自己将“入镜”一张遥远的宇宙影像。
卡西尼号的任务虽然已于2017年结束，但它对未来深空探索仍产生了深远影响。卡西尼号任务中积累的宝贵经验已被应用于NASA的“欧罗巴快帆”（Europa Clipper）任务。该任务借鉴卡西尼号的轨道巡游设计，于2024年发射，计划于2030年4月抵达木星，并对其冰封卫星欧罗巴展开数十次飞掠，以探索其地下是否存在可支持生命的环境。
图片来源: NASA/JPL-Caltech/SSI
