科学美国人60秒 木星月球将会被寻找生命迹象（在线收听）

“And this mission would be NASA’s first mission that is directly tasked with searching for signs of life on another world since the Viking Spacecraft were given that task back in the 1970s on the surface of Mars.”

自20世纪70年代海盗号宇宙飞船火星表面探测计划之后，这项任务是美国宇航局首次直接负责的在另一个世界探寻生命的迹象。

Kevin Hand of NASA’s Jet Propulsion Laboratory.

凯文·汉德来自美国宇航局喷气推进实验室。

“We talk about finding, searching for signs of life on some of these ocean worlds, and in particular these geologically active ocean worlds with rocky seafloors like Europa.”

我们讨论在这些海洋世界，特别是地质活跃的海洋世界内有多岩石的海底，例如欧罗巴，在那里发现的结果，以及寻找生命的迹象。

Hand spoke February 17th at the annual meeting of the American Association for the Advancement of Science in Boston. He’s the deputy project scientist for the Europa mission, which plans to send a lander to the ice-covered moon of Jupiter.

汉德在2月17日于波斯顿举行的美国科学促进会的年度会议上发表了上述讲话。汉德是欧罗巴任务的第二负责人，该任务计划向木星的冰雪覆盖的卫星发射着陆器。

“We’re talking about environments where life could be alive today…so these ice shells may serve as a window into the oceans below and oceanic material may be coming up to the surface. Where a mission like a lander could actually sample that material directly…and I’m the pre-project scientist for this mission. This is a mission that would reach the launch pad in the 2024–2025 time frame, it would land on Europa’s surface and operate for about 20-plus days.”

我们正在讨论现在生命可以生存的环境……，覆盖在卫星表面的冰层就会像海底的一个窗户一样，而这些海洋材料就会浮到表面。而着陆器就可以直接取样……我是这个项目的前期负责人。这一任务预计会在2024-2025年这一时间段进行。着陆器会降落在欧罗巴的表面，并将停留20余天。

The instrumentation that gets sent to Europa needs to be recognize signs of life in minute amounts.

发射到欧罗巴上的仪器需要在数分钟内识别生命迹象。

“A picomole of organics per gram of sample is one key requirement. Being able to detect cell number abundances to as low of a level as 100 cells per milliliter of ice acquired from Europa’s surface. We reached that benchmark by comparison to subglacial Lake Vostok here on Earth.

每克样本中有一皮摩尔有机物是一个关键要求。同时也要求在从欧罗巴获得的每毫升的冰中检测出100个细胞的丰富程度。我们通过和地球上的沃斯托克湖的冰川对比得出了上述指标。

And the size that the microscope in the model payload would need to be able characterize is down to a 0.2 micron diameter for any putative organisms collected in a surface sample of Europa. This mission is a bold, very exciting mission that marks NASA’s return to the direct search for life via in situ capabilities on a potentially inhabited ocean world beyond Earth.”

对于在欧罗巴表面收集任何假定的微生物，显微镜的模型载荷需要直径降0.2微米。这是一个大胆的,非常令人兴奋的任务,标志着美国宇航局可以在地球之外的可居住的海洋世界中，通过地形来直接寻找生命。