来源: http://news.nationalgeographic.com/2017/01/saturn-moon-titan-nasa-huygens-cassini-space-science

[1] Twelve years ago, a small spacecraft parachuted through a thick, extraterrestrial haze and drifted down toward an alien surface. 

[2] It punched a small hole in the icy ground, bounced, slid, and wobbled.

[3] After a few seconds, it came to rest in a damp floodplain on Titan, Saturn’s largest moon.

[1]十二年前，一艘小型宇宙飞船穿过厚厚的外星人的阴霾，向外掠过。

[2]它在冰冷的地面上打了一个小洞，弹跳，滑动，摇晃。

[3]几秒钟之后，它在土星最大的卫星土卫六的潮湿泛滥平台上休息。

[4] On January 14, 2005, the European Space Agency’s Huygens probe became the first robot explorer to touch the surface of this smoggy, orange moon and beam back detailed pictures. 

[5] Huygens frantically gathered data for about an hour before its batteries died and its mothership, NASA’s Cassini spacecraft, disappeared over the horizon.

[6] During its descent and those moments on the surface, the probe gathered enough data to give scientists a glimpse of an alien world that looks deceptively Earth-like.

[4] 2005年1月14日，欧洲航天局的惠更斯探测器成为第一个触摸这个烟雾，橙色月亮和光束背面详细图片的机器人探险家。

[5]惠更斯疯狂地收集了大约一个小时的数据，然后它的电池就死了，它的母舰，美国宇航局的卡西尼号太空船在地平线上消失了。

[6]在它的下降和表面上的那些时刻，探测器收集了足够的数据，让科学家们可以一瞥看起来像地球一样的外星世界。

[7] Nearly 900 million miles from the sun, temperatures on Titan are so low that ice is as hard as rock and organic compounds like ethane and methane—which are normally gases on Earth—are chilled into liquids that pool and flow into enormous lakes and seas.

[8] But with its mountains, rain, winds, and waves, 3,200-mile-wide Titan is really more like a planet than just another dead, cratered moon. 

[9] It not only has those oily seas on its surface, but it also harbors a buried ocean of liquid water, making it among the best places to search for life beyond Earth.

[7]距离太阳近9亿英里，土卫六的温度非常低，冰块和岩石一样坚硬，有机化合物如乙烷和甲烷 - 通常是地球上的气体 - 被冷却成液体，汇集并流入巨大的湖泊 和海洋。

[8]但是有了它的山脉，雨，风和海浪，3,200英里宽的土卫六更像是一颗行星，而不仅仅是另一个死去的月球陨石坑。

[9]它不仅在其表面有油海，而且还有一个被埋没的液态海洋，使其成为寻找地球以外生命的最佳场所。

[10] “Titan is kind of a double ocean world,” said planetary scientist Sarah Hörst of the Johns Hopkins University. 

[11] “In principle, there’s the possibility that it has both life as we know it and life as we don’t know it.”

PIERCING THE HAZE

[12] The Huygens probe hitchhiked to the Saturn system on board NASA’s Cassini spacecraft, which dropped off the lander not long after pulling into orbit around the ringed planet.

[10]“土卫六是一个双重海洋世界，”约翰霍普金斯大学的行星科学家萨拉赫斯特说。

[11]“原则上，它有可能既有我们所知的生命，也有我们不知道的生活。”

刺痛HAZE

[12]惠更斯的探测器搭载在美国宇航局的卡西尼号太空船上的土星系统上，该太空船在环绕着环状行星进入轨道后不久就从着陆器上掉了下来。

[13] Though Cassini had been assigned the task of exploring Saturn and its many moons, that little probe—named after the Dutch astronomer Christiaan Huygens—had just one target in sight: Titan, which is shrouded in a puffy atmosphere that mostly obscures the moon’s surface.

[14] After a 20-day journey to Titan, Huygens sank through the moon's atmosphere for more than two hours before landing on a frigid plain, where temperatures are nearly 300 degrees below zero, and gathering data.

[15] “Huygens revealed Titan’s environment directly, whereas most of what was 'known' before was rather indirectly determined,” says the University of Arizona’s Ralph Lorenz. 

[13]虽然卡西尼被分配了探索土星及其许多卫星的任务，但这个以荷兰天文学家克里斯蒂安惠更斯命名的小探测器只有一个目标：泰坦，它被笼罩在一个浮肿的气氛中，大部分都掩盖了 月亮的表面。

[14]在经历了为期20天的土卫六之旅后，惠更斯在月球大气层中沉没了两个多小时，然后降落在寒冷的平原上，温度接近零下300度，并收集数据。

[15]“惠更斯直接揭示了土卫六的环境，而之前'已知'的大部分内容都是间接决定的，”亚利桑那大学的拉尔夫洛伦兹说。

[16] “It showed us the surface close up.”

[17] Data showed us highlands, ravines, and channels carved by liquids, as well as winds whipping through Titan’s nitrogen atmosphere. 

[18] Measurements from the surface showed the probe didn’t land in a dry desert, and that some kind of liquid was moistening the sand beneath it.

[16]“它向我们展示了表面的特写。”

[17]数据显示我们的高地，沟壑和通过液体雕刻的通道，以及通过泰坦的氮气氛吹过的风。

[18]从表面测量显示探测器没有落在干燥的沙漠中，并且某种液体润湿了它下面的沙子。

[19] Huygens’ atmospheric measurements have since helped scientists reconstruct the composition of Titan’s ancient atmosphere (probably a combination of ammonia and methane) and study how organic molecules can behave in a predominantly nitrogen atmosphere, as Earth’s once was before life evolved and oxygen became abundant.

[20] “It’s the only other substantial nitrogen atmosphere besides ours,” Hörst says. “Presumably, a lot of the chemistry in Titan’s atmosphere could have been happening on the early Earth, before oxygen.”

MIRROR MOON

[21] The Huygens mission marks the first and—so far—last time humans set a spacecraft on a moon other than our own.

[19]惠更斯的大气测量已经帮助科学家们重建泰坦古老大气层（可能是氨和甲烷的组合）的组成，并研究有机分子如何在主要的氮气氛中表现，就像地球曾经在生命进化和氧气成为之前一样 丰富。

[20]“这是除了我们之外唯一的其他大量氮气氛，”赫尔斯特说。 “据推测，土卫六大气中的大部分化学反应可能发生在地球早期，氧气之前。”

MIRROR MOON

[21]惠更斯任务标志着人类在月球上设置航天器的第一次也是最后一次，而不是我们自己的。

[22] A mission called the Titan Mare Explorer was once among NASA’s top picks for a future interplanetary adventure. 

[23] Had it been selected, that mission would have sent a space boat to explore Ligeia Mare, one of Titan’s largest northern seas.

[24]Made of runny, liquid hydrocarbons, the moon’s surface seas could be home to life with a completely different chemistry than ours.

[22]一项名为Titan Mare Explorer的任务曾经是NASA未来星际探险的首选。

[23]如果它被选中，该任务将派遣一艘太空船探索土卫六最大的北海之一Ligeia Mare。

[24]由流动的液态碳氢化合物制成，月球表面海洋可能是生命的家园，其化学成分与我们完全不同。

[25] “That’s a test for a diversity of life: Could you also find life that uses a different liquid than life on Earth?” Hörst says.

[26] In addition, humanity will soon lose its ambassador to the whole Saturn system: Cassini’s mission ends later this year, with a dramatic plunge into the giant planet. 

[27] Still, even after they’re gone, data gathered by spacecraft like Huygens and Cassini can continue to offer new clues to our solar system and help scientists build the case for future missions.

[25]“这是对生活多样性的考验：你能否发现使用与地球上生命不同的液体的生命？”赫尔斯特说。

[26]此外，人类将很快失去其对整个土星系统的使命：卡西尼号的使命将在今年晚些时候结束，并将大幅下降到这个巨大的星球。

[27]尽管如此，即使在它们消失之后，像惠更斯和卡西尼号这样的航天器收集的数据也可以继续为我们的太阳系提供新的线索，并帮助科学家为未来的任务建立案例。

[28] With Titan, we’ve found a world that is both totally alien and yet somewhat familiar. 

[29] Seasonal rains darken its plains, it’s rich in organic molecules, and a wintry vortex decorates its poles (complete with hydrogen cyanide clouds).

[30] “Titan's appeal is its mix of the familiar and exotic,” Lorenz says. 

[28]通过泰坦，我们发现了一个既完全陌生又又有点熟悉的世界。

[29]季节性降雨使其平原变暗，它富含有机分子，冬季的漩涡装饰着它的两极（完整的氰化氢云）。

[30]“泰坦的吸引力在于其熟悉和异国情调的结合，”洛伦兹说。

[31] “Ultra-low temperatures, ices, organics, liquid methane—but making familiar rain, rivers, dunes, seas.”

[32] Simply put, it’s a world that scientists would dearly love to get to know a little bit better, not only because of the excitement of exploring extraterrestrial terrains, but because it can teach us more about this planet we call home.

[33] “Titan is so active and has so many Earth-like processes, it’s such a good test for our fundamental understanding of how planets work,” Hörst says.

[31]“超低温，冰，有机物，液态甲烷 - 但让人熟悉的雨，河流，沙丘，海洋。”

[32]简单地说，这是一个科学家非常喜欢更好地了解的世界，不仅因为探索外星地形的兴奋，而且因为它可以教会我们更多关于这个星球的信息，我们称之为家。

[33]“泰坦是如此活跃，有如此多的类似地球的过程，这对我们对行星如何运作的基本理解是一个很好的考验，”赫尔斯特说。