(单词翻译:单击)
We've added a lot to the classic picture of Mars in the last few years, especially where water is concerned.
过去几年间，我们已经对火星的组成结构有了很多猜想，尤其是与水有关的方面。
Between the pretty strong evidence of salty liquid water scattered across the surface, not to mention the giant lake that might be hidden deep under the south pole,
我们有切实的证据表明火星表面有液态盐水分布，更不用说南极下方深处掩藏的巨大湖泊了。
it seems like there's a surprising amount of liquid water over there.
似乎水星的液态水含量令人震惊。
And in a paper published this week in Nature Geoscience, researchers found that all this water we've been finding might actually contain enough oxygen for certain forms of life to survive there.
本周，《自然地球科学》上发布了一篇论文。本文作者发现，我们发现的这些水可能含有足够的氧元素，可以支持某些形式的生命生存。
Not just simple unicellular microbes, either.
而不只是单细胞微生物。
In some places, there might even be enough oxygen for more complex life to survive.
而有些地方的含氧量可能不足以支持复杂生命的生存。
So water is super important to the search for life on other worlds, because as far as we know, life can't survive without it.
所以，要在外星世界寻找生命，水的存在就极为重要，因为根据我们目前了解的信息，没有水就没有生命。
But of course, there's a big difference between figuring out whether life could survive on Mars and actually finding life there.
不过，当然了，弄清楚火星是否能支持生命生存与火星是否有生命存在是两回事儿。
And even with the evidence of liquid water, we're still working on that first one.
即便有证据表明液态水存在，我们依然还在发现生命存在的路上。
The main problem is that the water on Mars is full of a type of salt called perchlorates, which happen to be pretty toxic to life as we know it.
主要问题在于：火星上的水里，一种盐的浓度很高，这种盐就是高氯酸盐。而高氯酸盐对生命是有害的。
But we know that life can adapt to all kinds of extreme conditions.
但我们都知道生命是可以适应各种极端环境的。
And when we talked to Vlada Stamenkovic, one of the authors on the new paper, he noted in a place like Mars where there are perchlorates everywhere, adapting to them might just be normal.
我们跟这篇新论文的一位作者弗拉达聊天时，他表示，像火星这样的地方，到处都是高氯酸盐，适应其存在是很正常的事。
Still, when scientists talk about life surviving on Mars, they're pretty much always referring to anaerobic life, simple, unicellular life that doesn't need oxygen to survive.
不过，每次科学家讨论火星上有生命存在的事情时，他们指的往往是厌氧的单细胞生物，它们不需要氧气就能生存。
More complex, aerobic life does require oxygen, and since there's not much of it on Mars, most researchers assumed aerobic life wouldn't be able to survive there. At least, until now.
更加复杂的需氧生物确实需要氧气，而由于火星上的氧气非常少，所以大多数科学家都会假定需氧生物无法在火星生存。至少目前为止是这样的。
Other recent studies have found that aerobic life doesn't need quite as much dissolved oxygen to survive in water as we used to think, only 0.032 parts per billion for single-celled microbes, which is not a lot.
最近还有一些研究发现，需氧生物需要的溶氧量不像我们过去想的那样多。单细胞微生物中只需要0.032%/10亿浓度的溶氧量，这个浓度不是很高。
For comparison, oceans on Earth have about 200 thousand times that.
对比一下，地球海洋的浓度是这个浓度的近20万倍。
So the authors of this week's paper wanted to see if the oxygen content of Martian brines would be enough to support aerobic life.
所以本文作者想看看火星盐水中氧的含量是否足以支持需氧生物。
When they put together a model of how oxygen would dissolve in the brine based on the conditions on Mars,
他们汇总了一个模型，模型显示火星环境下氧气在盐水中的溶解率。
they found that there were large areas of the planet where the brine would have enough oxygen to support aerobic life.
据此他们发现，火星上有很大一片区域中有足够的氧气，可以支持需氧生物的存在。
And on about 7% of the surface, the model showed that there might even be enough oxygen to support more complex, multicellular life, like sponges,
该模型显示，火星表面有7%的地方甚至可能也有足够的氧气，可以支撑更为复杂的多细胞生物，比如海绵动物。
which need about 2000 times as much as single-celled aerobic life.
是单细胞需氧生物的近200倍。
The researchers focused on the small brine deposits close to the Martian surface, not the giant lake we think might exist about a kilometer and a half below the planet's south pole.
这些科学家专注于火星表面附近的面积不大的盐水区，而不是南极下方1.5公里左右的大型湖泊。
But they said that according to their results, the lake would probably have lots of dissolved oxygen, too, as long as it has a reliable source of the stuff, like from the atmosphere or from radiation breaking down water molecules.
但他们表示，结果表明，湖中也可能有大量溶解氧，只要有可靠的水源就会如此，比如大气层或者辐射分解的水分子。
Obviously, none of this means there is aerobic life on Mars, or that life exists there at all.
显然，这些都无法证明火星上存在需氧生物，也无法证明火星上有生命存在。
But Stamenkovic also pointed out that oxygen was a huge factor in the evolution of complex life on Earth.
但弗拉达也指出，氧是地球复杂生命进化的重要条件。
So finding enough oxygen to support aerobic life right next door opens up a lot of new possibilities in the search for life on Mars, and maybe on other worlds, too.
所以，在地球附近的星体上发现有足够的氧气支持需氧生物，这为我们探索火星乃至其他星球的生命提供了新的可能性。
Meanwhile, NASA's InSight lander is on its way to Mars, set to touch down in late November.
与此同时，美国宇航局的洞察号探测器正在飞往火星的路上，预计11月下旬着陆。
It's not designed to study places where we think life might be able to survive, since it's so hard to make sure we don't contaminate those places with microbial hitchhikers from Earth.
设计洞察号的初衷不是研究哪些地方能生存，因为很难确保我们不会因为把地球上的微生物带到这片区域而污染了这个地方。
Instead, InSight is going to study the planet's interior to learn more about how rocky planets formed in the Solar System.
洞察号的任务是研究火星的内部结构，了解更多有关火星在太阳系里形成过程的信息。
And last week, NASA released a video with more details about how exactly that will work.
上周，美国宇航局发布了一则视频，里面有更多信息表明洞察号的工作方式。
It involves....the claw.... Did I do a good job of that? Seriously, though.
包括钳形工具，我描述的可能不够准确。
Since InSight's mission is to study the Martian interior, which we've never properly done before, its scientific instruments need to be in direct contact with the surface.
鉴于洞察号的任务是研究火星的内部结构，而这又是我们此前从未好好做过的事情，所以洞察号所需要的科学仪器需要跟火星的表面进行直接的接触。
So the lander's robotic arm has a claw attached to the end that it will use to pick up those instruments and place them on the ground.
所以着陆器的机械臂上配有一个钳形结构，跟尾部黏在一起。机械臂会靠这个钳形结构来抓起仪器，并把仪器放在地面上。
In other words, the highly-sophisticated robotic lander we're sending to another planet is basically a glorified claw machine.
换言之，我们送往其他行星的这个高度精密的机械着陆器，其实是美化了的钳形工具而已。
Unlike the machines you dump money into at the arcade, though, the lander's mechanism is designed to actually pick things up.
不过，这个机器跟我们在游乐场投币的机器不同，虽然它的基本原理是要把东西捡起来。
The mission team considered a few other options, but there were problems with all of them.
负责该任务的团队考虑了其他的一些选择，但每种选择都有各自的问题存在。
A magnet, for example, might not work if too much dust got in the way.
比如，如果用磁铁的话，如果中间有灰尘挡路的话，就无法工作。
It's actually a pretty cool bit of engineering, the mechanism opens up by heating up wax, which then expands, putting pressure on a rod that opens the claw.
其实这其中用到了很酷的工程学知识，其基本原理是给蜡加热，根据受热膨胀的原理，棒子就会受到压力，然后打开钳形结构。
Then you just lower the open claw onto whatever instrument you want to move.
然后，我们只需要将张开的钳形结构放在想要移动的仪器上就可以了。
They all have hooks for the claw to grab onto.
所以仪器上都自带挂钩，方便抓住。
When the wax cools, a spring pushes the rod back into place, closing the claw.
等蜡降温后，弹簧会将棒子收回到原地，然后爪子就闭合了。
And once it's in place, it will stay closed even with the instrument pulling down on it, unlike the claws in arcade machines, which are designed to open when something pulls down on them.
棒子回到原地后，爪子会保持闭合状态，即便仪器对它产生向下的推力也是如此。这就跟游乐场里的机器不一样了，因为后者在受到向下的推力时会张开爪子。
So if InSight happens to find any little three-eyed green aliens waiting for it on Mars, they won't stand a chance.
所以，一旦洞察号碰巧在火星上发现什么三只眼的绿色外星人的话，外星人怕是跑不掉了。
Thanks for watching this episode of SciShow Space News!
感谢收看本期的《太空科学秀》！
And thanks especially to our Patreon President of Space SR Foxley and our community on Patreon for supporting what we do.
尤其要感谢President of Space，也就是SR Foxley，以及我们的忠实粉丝。
You might have seen our livestream extravaganza earlier this week, where we tested some fun experiments, did a live quiz show, and tried very hard to blow up a pumpkin.
这一周，大家可能已经看过我们的现场直播了。直播里，我们测试了一些有趣的实验，还有现场的小测验，还试着用南瓜搞怪。
But most importantly, we got to connect with people who share our passion for spreading scientific knowledge to anyone who wants to learn.
但最重要的是，我们得以跟有共同兴趣的人接触，传播科学知识给想学的人。
We wouldn't be able to do this without your help.
没有你们的帮助，我们做不到这一点。
If you're not yet a patron and want to know more, just check out patreon.com/scishow.
如果屏幕那头的你还不是我们的粉丝，但还想要了解更多的话，欢迎访问patreon.com/scishow。
