NASA刚刚发现木星的卫星喷出大量水蒸气

NASA刚刚发现木星的卫星喷出大量水蒸气

When it comes to candidates for alien life in our solar neighborhood, Europa is the apple of every scientist's eye.

当说到在我们的太阳系附近可能存在外星生命时，木卫二是每个科学家一定会提出的。

Under a thick crust of ice, Europa might have an ocean warmed by tidal interactions with Jupiter. (Photo: NASA/JPL/Ted Stryk)

The moon — one of 79 whirling around Jupiter — has already offered a few tantalizing hints. Earlier this year, a detailed analysis of the satellite revealed that it’s covered in salt, suggesting a vast, very Earth-like ocean beneath its icy enamel.

这颗围绕木星旋转的79颗卫星之一已经给出了一些诱人的暗示。今年早些时候，对这颗卫星的详细分析显示，它被盐覆盖，表明在它冰冷的珐琅质下有一个巨大的、非常像地球的海洋。

And now, NASA is hailing an even bigger breakthrough. According to a research paper published in the journal Nature Astronomy, plumes of water vapor are bursting from the moon’s surface.

现在，美国宇航局正在欢呼一个更大的突破。根据发表在《自然天文学》杂志上的一篇研究论文，大量的水蒸气正从木卫二表面喷涌而出。

They’re scarcely detectable from Earth — just one of 17 observations by the W. M. Keck Observatory in Hawaii was able to pick up on a faint plume released from Europa’s surface.

它们在地球上几乎无法被探测到——夏威夷W. M. Keck天文台的17次观测中，只有一次能够探测到从木卫二表面释放出的微弱羽状物。

But it’s enough to dramatically heat up the hunt for life beyond our planet.

但这足以极大地加剧对地球以外生命的搜寻。

"While scientists have not yet detected liquid water directly, we've found the next best thing: water in vapor form," lead researcher and NASA planetary scientist Lucas Paganini noted in a NASA release.

“虽然科学家们还没有直接探测到液态水，但我们已经发现了下一个最好的东西:水蒸气形式的水，”首席研究员、NASA行星科学家卢卡斯·帕格尼尼在NASA的一次发布会上说。

And although spectrographs taken by the W. M. Keck Observatory could just barely make out the plumes, scientists say the moon is releasing a massive amount of water vapor — enough to fill an Olympic-size swimming pool within minutes.

尽管W. M. Keck天文台的摄谱仪只能勉强分辨出这些羽状物，但科学家们说，月球正在释放大量的水蒸气——几分钟内就足以填满一个奥运会规模的游泳池。

That adds credence to the suspicion that the ocean lurking beneath Europa’s frozen shell is incredibly vast. NASA suspects that shell is between 10 and 15 miles thick. And below, lies a saltwater ocean that plumbs a dizzying depth of anywhere from 40 to 100 miles. Compare that to the 2.3-mile average depth of Earth’s oceans.

这使人们更加怀疑，在木卫二冰冻的外壳下隐藏的海洋是多么的巨大。NASA怀疑，外壳厚度在10到15英里之间。下面是一片咸水海洋，令人眼花缭乱的深度从40英里到100英里不等。相比之下，地球海洋的平均深度为2.3英里。

And suddenly, we’re swimming in all kinds of possibilities.

突然之间，我们发现了多种可能性。

“We performed diligent safety checks to remove possible contaminants in ground-based observations," Planetary scientist Avi Mandell notes in the NASa statement. “But, eventually, we'll have to get closer to Europa to see what's really going on.

行星科学家阿维·曼德尔在NASA的声明中指出:“我们进行了仔细的安全检查，以清除地面观测中可能存在的污染物。”“但是，最终，我们将不得不靠近木卫二去看看到底发生了什么。

NASA is already planning to dip a toe in those waters.

NASA已经计划涉足这些领域。

The space agency’s Europa Clipper mission could put a spacecraft, brimming with cameras and spectrometers, in Jupiter’s orbit as early as 2023. From there, it will perform 45 flybys of the icy orb, performing the most detailed analysis of the moon’s surface yet.

早在2023年，美国宇航局的木卫二快船任务就能将一艘装有摄像机和光谱仪的宇宙飞船送入木星轨道。在那里，它将对这个冰冷的星球进行45次飞掠，对木卫二表面进行迄今为止最详细的分析。