2025年10月12日
欧罗巴上的所有水
插图来源与版权: Kevin Hand (JPL/Caltech), Jack Cook (Woods Hole Oceanographic Institution), & Howard Perlman (USGS)
说明: 木星的卫星欧罗巴有多少是由水组成的？虽然没有人能确定，但可能相当多。根据伽利略探测器在1995年至2003年期间探索木星系统时获得的数据，欧罗巴在其表面冰层之下拥有一个深邃的全球性液态水海洋。这个地下海洋加上冰层的平均深度可能超过100公里。采用100公里深度的高端估计值，如果欧罗巴上的所有水都被集中成一个球体，它的半径将超过800公里。这个引人注目的插图将欧罗巴上所有水的假想球体与欧罗巴本身的大小（左）进行了比较-同样地也与地球上的所有水进行了比较。欧罗巴的全球地下海洋的体积可能大于地球的海洋，这使其成为在我们太阳系中寻找外星生命的诱人目的地。NASA的机器人欧罗巴快船于去年发射以进行调查。
明日的图片: lemmon tail
Due to the lapse in federal government funding, NASA is not updating APOD website. We sincerely regret this inconvenience.
由于美国联邦政府资金中断，NASA目前暂停更新APOD网站。对此带来的不便，我们深感抱歉。
英文原文:
Explanation: How much of Jupiter’s moon Europa is made of water? No one is sure, but probably a lot. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa possesses a deep, global ocean of liquid water beneath a layer of surface ice. The subsurface ocean plus ice layer could descend over 100 kilometers in average depth. Adopting a high-end estimate of 100 kilometers depth, if all the water on Europa were gathered into a ball , it would have a radius of over 800 kilometers. To scale, this intriguing illustration compares that hypothetical ball of all the water on Europa to the size of Europa itself (left) – and similarly to all the water on planet Earth . With a volume possibly greater than Earth’s oceans, the global subsurface ocean on Europa is a tantalizing destination to search for extraterrestrial life in our Solar System. NASA ‘s robotic Europa Clipper launched last year to investigate.
