木星附近的卫星
影像来源与版权:Betul Turksoy

说明:5月20日,一轮近乎圆满的月亮和木星共享了这片望远镜视野。这幅单张曝光影像拍摄于一片行云遮挡月光之时,它呈现了我们美丽地球自己的大型天然卫星的熟悉面孔,以及明亮的木星(位于右下方)和它的一些伽利略卫星。从左到右排列在木星附近的小光点依次是木卫三、木卫二、木星和木卫四。(那不是你屏幕上的灰尘…)。我们自己的天然卫星距离更近更亮,所以显得非常庞大。但是,木卫三和木卫四的体积比月球还要大,而水世界木卫二只比月球稍小一点。实际上,在太阳系最大的六颗行星卫星中,土星的卫星土卫六在画面中看不到,而排行第四的伽利略卫星木卫一则被庞大的气态巨星所遮挡。
翻译:北京天文馆

Moons Near Jupiter
Image Credit & Copyright: Betul Turksoy

Explanation: On May 20, a nearly Full Moon and Jupiter shared this telephoto field of view. Captured when a passing cloud bank dimmed the moonlight, the single exposure reveals the familiar face of our fair planet’s own large natural satellite, along with bright Jupiter (lower right) and some of its Galilean moons. Lined up left to right the tiny pinpricks of light near Jupiter are Ganymede, Europa, [Jupiter] and Callisto. (That’s not just dust on your screen…) Closer and brighter, our own natural satellite appears to loom large. But Ganymede, and Callisto are physically larger than Earth’s Moon, while water world Europa is only slightly smaller. In fact, of the Solar System’s six largest planetary satellites, Saturn’s moon Titan is missing from the scene and a fourth Galilean moon, Io, is hidden by our ruling gas giant.
Astronomy Picture of the Day 05/23/2019