木卫凌越木星

2023年6月13日

Moons Across Jupiter
Image Credit: NASA; ESA, JPL, Cassini Imaging Team, SSI; Processing: Kevin M. Gill

Explanation: Jupiter’s moons circle Jupiter. The featured video depicts Europa and Io, two of Jupiter’s largest moons, crossing in front of the grand planet’s Great Red Spot, the largest known storm system in our Solar System. The video was composed from images taken by the robotic Cassini spacecraft as it passed Jupiter in 2000, on its way to Saturn. The two moons visible are volcanic Io, in the distance, and icy Europa. In the time-lapse video, Europa appears to overtake Io, which is odd because Io is closer to Jupiter and moves faster. The explanation is that the motion of the fast Cassini spacecraft changes the camera location significantly during imaging. Jupiter is currently being visited by NASA‘s robotic Juno spacecraft, while ESA‘s Jupiter Icy Moons Explorer (JUICE), launched in April, is enroute.

Tomorrow’s picture: interstellar predator

木卫凌越木星
影像提供: NASA; ESA, JPL, Cassini Imaging Team, SSI; 影像处理: Kevin M. Gill

说明: 木星的卫星绕着木星运行。这部主题影片呈现木卫二和木卫一这两颗木星的大卫星，在这颗行星的大红斑、太阳系里现知最大的风暴系统前方交错的景观。这部影片是由卡西尼号宇宙飞船，在2000年路过木星前往土星的途中，所拍下的多幅影像组合而成。影片中所见的两颗卫星，分别是较远处的火山卫星木卫一及冰卫星木卫二。在这部缩时影片里，木卫二似乎追过了木卫一；这是很让人困惑的景观，因为木卫一离木星较近，移动也较快速。这现象的解释是：卡西尼号宇宙飞船在高速移动，造成取像时的相机位置出现显著的改变。目前正探索木星的宇宙飞船是美国航空航天局的朱诺号，而在今年4月发射的欧洲航天局木星冰卫探测器（JUICE），则在前往木星的途中。

明日的图片: interstellar predator