字幕菌：cnszw
校对菌：myname69
双语调整：那白岚
后期压制：那白岚
出品：纪录片之家
最初 宇宙是一片黑暗 In the beginning, there was darkness,
紧接着一声巨响 混沌初开 and then, bang, giving birth
时间 空间和物质 to an endless, expanding existence
开始不断膨胀 of time,space and matter.
每天 我们都在解密这神秘莫测 Every day, new discoveries are unlocking the mysterious,
令人疯狂的极端之地 the mind-blowing, the deadly secrets
宇宙 of a place we call the universe.
火星人在哪里 Where are the Martians?
在毒气笼罩的红色星球表面 On the red planet's, poison-packed surface
抑或是新发现的水源中 or in newly found sources of water?
火星生命从致命大碰撞中生存下来了吗 Did Martian life survive an apocalyptic attack?
它们是微生物 还是大怪物 Are Martians like microbial or monstrous?
最终答案即将揭晓 at last, the answers are here
就在《火星新证据》 In Mars: the new evidence.
宇宙第五季EP02火星新证据
肯尼迪航天中心
2010年4月15日
我相信我们能将人类送入火星轨道 I believe we can send humans to orbit Mars
并让他们安全返航 and return them safely to Earth.
紧接着实现在火星登陆的计划 And a landing on Mars will follow.
当我们降落在火星时 When we land on Mars,
也许会看到成千上万的火星人 there may be billions of Martians waiting for us.
他们的长相可能不是这样 Only they probably won't t look like this
也不是这样 or this,
而是这样 but like this.
微生物 细菌进化到在此星球上生存生长 Microbes, bacteria evolved to survive on a planet
这里的大气压力只有地球的1% with 1% of Earth's atmospheric pressure,
还是个温度能从220摄氏度 an arid world where temperatures can plunge
骤降至零下的干旱之地 to 220 degrees below zero.
尽管表层环境看起来如此恶劣 Now, even if that upper-surface is so nasty,
但并不意味着 that doesn't t mean
掩藏在下面的境况也如此 that just a little ways under the surface,
这里是火星上微生物的极乐天堂 Wouldn't be a much happier place for microbial life on Mars.
布鲁斯·贝茨 美国行星协会
火星上有生命存在吗 Is there life on Mars?
十年前 我的答案和现在迥然不同 Just a decade ago, my answer would have been very different than it is today
吉姆·贝尔 康奈尔大学
因为这些年获取了大量信息 because we've learnt so much.
数十年前 A few decades ago,
这看起来像是科幻剧 it would have seemed like science fiction.
然而现在我们知道 在地球上 But we now know that on Earth,
一些微生物聚集在海底的热泉周围 {\c
另一些生长在南极地区冰层下 others thrive in pockets of liquid water
12英尺中的少量液态水里 inside 12 feet of antarctic ice.
我们对于地球微生物的了解已经很深入了 Our knowledge of microbial life on Earth has increased so much
阿什温·瓦萨瓦达 美国宇航局/喷射推进实验室
有时我想 某些原始微生物是不是可能 that, I think, you know, there's still a good chance that some kind of
在火星形成并存在的呢 primitive life may have formed on Mars and existed there at some point.
生命是如何在火星上形成的呢 How could life have first formed on Mars?
也许是由于一个闪电 Maybe with a flash of lightning.
2006年的春天 The spring of 2006.
尽管当时一些科学家 Even as some scientists are
声称火星上没有闪电 claiming Mars doesn't t have lightning,
地球上的微波探测器发现 Earth-based microwave detectors find it
火星上有充满静电的红色尘暴 in friction-filled storms of red dust.
这并不是我们所熟知的 But it's not lightning like we know it,
劳拉·丹利 格里菲斯天文台
暴风雨前的闪电 associated with rainstorms.
火星上没有雨 Well, it doesn't rain on Mars.
我们称之为干闪电 It's what's called dry lightning.
这种干闪电 或者说静电 And this dry lightning, or static electricity,
可能就是火星生命起源的契机 could have been the trigger for Martian life.
一旦闪电 就能够产生一种 Once you have lightning, you've got a new source of energy
改变大气中化学成分的新能量 that can affect your chemistry and alter things in the atmosphere,
一定程度上来说 即使表面也是这样 even on the surface, at some level.
一个著名的实验试图复制 A famous experiment seeking to replicate
地球生命的起源 the creation of life on Earth.
在水和普通气体的混合物中通上电流 Ran an electric current through a mix of water and common gases,
产生一种溶液 creating a soup,
包含有机化合物 containing organic compounds
和生命基本组成物 氨基酸 and the building blocks of life: amino acids.
通过电流刺激 By hitting things, with electrical discharges,
虽然不能创造生命 you could not necessarily generate life,
但也许可以营造生命起源的先决条件 but maybe make the preconditions for life.
干闪电确是火星生命起源的助推器吗 But did dry lightning,, help jumpstart life on Mars?
还是彻底破坏任何生存可能的杀手 Or did it kill the chance for any life at all?
火星上的闪电能创造过氧化氢等物质 Lightning on Mars could create things like hydrogen peroxide,
这些物质将生成其他化学成分 which could then lead to other chemicals that would
摧毁火星表面的一切有机物质 destroy organic material and sterilize the surface.
是生之希望 还是死之深渊 Life-giving jumper cable or fatal electric chair.
我们仍然不清楚 The jury is still out on
尘暴闪电对火星有什么影响 what dust storm lightning has done to Mars.
我们总是刚以为已经了解 Well, what always happens with Mars is about the time
火星的时候 we think we understand it,
又会有新的发现 让我们意识到 we discover new things that make us realize
仍有很多谜题需要解开 we still have a lot of mysteries to solve.
如何在4800万英里之外的 So how do you find bacteria too small to be seen,
星球表面之下找到极为微小的细菌呢 living under the surface of a planet, 48 million miles away?
最可能繁殖的生命体 The life that's most likely to be prolific,
有机物含量最多的生命体 the life that you'd find the most number of organisms,
琳达·缇·埃尔金-坦通 麻省理工学院
如果确实存在 会是最难以获取的 if they did exits, is the one that's hardest to find of all.
就像攀岩者 科学家们在火星上 Like climbers, scientists look for life on Mars
通过相互关联寻找生命 by making connections,
结合观察结果与推论 linking this observation to that deduction,
以期求得最后的正确答案 hoping the evidence leads in the right direction.
但如果一个环节脱节 And if the facts aren't there,
只能重新开始 you start over.
寻找生命很困难 It's hard to look for life.
这项课题的设计者曾经说过 So the mission designers have said,
我们先找到是否有 well, let's s first figure out
适合生存之地 if there are habitable places,
是否有适合生命延续之地 if there are places that would be friendly to life.
众所周知 生命所需的关键元素便是水 And the key element for life as we know it is water.
地球上所有生命的延续都需要液态水 On Earth, liquid water is required for life.
即便处于冰川之中 Even if it's a small pocket in the heart of a glacier,
仍需要液态水 you still need the fluid nature of water
来维持生命 for the processes of life to take place.
根据早期空间探测站的照片显示 According to early space probe photos,
火星只是一个沉寂的红色岩石 Mars was just a dead red rock.
稀薄的大气大部分由二氧化碳组成 Its thin atmosphere was mostly carbon dioxide,,,
极地似乎有冰层覆盖 and so it seemed, were the polar ice caps.
在70年代 我们曾经想过 You know, in the seventies, we might have expected
火星上不存在生命和水 that there was no possible water or life on Mars.
现在所拍摄的照片却大不相同了 The picture is much different today.
21世纪以来 In the 21st century,
更加先进的空间探测器已证明 more advanced space probes have revealed
之前的许多结论是错误的 that a lot of the earlier information was wrong.
结果显示 火星极地覆盖冰川的含水量 It turns out, there's about 100 times as much H2O in Mars' polar caps
是北美洲五大湖含水量的百倍 as in all five of north America's great lakes.
就算是现在 极地冰川的含水量 So even in the polar caps today, there's s probably
也足够覆盖火星表面 enough water to cover the surface,
达20至30英尺深 about 20, 30 feet deep.
目前并不是证明 But it's really not about
火星上是否存在水 whether we think there's water on Mars,
而是要证实火星上是否存在液态水 but whether there's liquid water on Mars.
这是个关键的问题 That's the key question,
因为在早期的火星 微生物的进化 because even microbial life could not have evolved on Mars
离不开液态水的存在 unless there was liquid water early in the planet's s history.
为了在火星上寻找液态水 In order to find liquid water on Mars,
我们想尽了一切办法 we actually look in a whole variety of ways.
从1997年到2006年 From 1997 through 2006,
美国宇航局火星全球勘探者号 NASA's s Mars Global Surveyor
用高敏感度的光谱仪 searches for water-based minerals
探测含水基的矿物质 using a highly sensitive spectrometer.
每一种化学物质都有 Every chemical element has a particular
其特有的标记 signature associated with it,
就如同指纹 a sort of fingerprint
当光与之作用时 and when light interacts with it,
克里福德·约翰逊 南加州大学
它会以一种特有的方式 it reemits that light in a very specific way
将光反射回来 that's characteristic to that given element
因此只需观察元素反射的光 and so that's telling you what things made of
就可以知道元素的组成了 by just looking at the light they emit.
这与人耳能分辨 It's similar to the way the human ear
特定的震动是同一个道理 can pick out specific vibrations.
一些音符声音洪亮 Some notes boom out
另一些音符却很低沉 other notes are not so loud.
同理 In much the same way,
光谱学家对于筛选 spectroscopists are interested in
那些特定的光线非常感兴趣 selecting out those particular lines.
勘探者太空船偶然发现了 The surveyor spacecraft,
可反射光线的矿土 hits spectrographic paydirt:
赤铁矿 一种铁与氧的化合物 hematite, a combination of iron and oxygen.
其存在表明 Hematite shows that
远古时代的火星可能有液态水存在 ancient Mars could have had flowing water
因为这种矿物在地球上也有 because the mineral is also found on Earth,
就存在于曾有液态水作用的环境下 in environments that once interacted with liquid water.
这些圆石来自犹他州 These round rocks from Utah,
它们是在砂岩中形成的 they formed in a sandstone
液态水从岩石中的小孔流过 by fluid water flowing inside the pores of the rock
带来了铁元素 and moving iron around
这事实上是铁元素 so that the iron actually
将小球粘合成型的 cements together these little spheres
火星上发现的小球 and the ones on Mars are quite
要比这个小的多 a bit smaller than these,
但形成的过程应该是相同的 but they're thought to form the same way.
勘探者号的任务结束了 The Surveyor's mission is over,
如今 but today,
有5个探测器在对火星进行拍照及测量 five probes are taking pictures and measurements of Mars.
欧洲航天局的火星快车探测器 Europe's Mars Express
环绕着火星的赤道航行 {\c
美国宇航局的火星奥德赛 NASA's Mars Odyssey
还有更加现代化的火星探测轨道卫星 and the more a recent Mars Reconnaissance Orbiter
简称MRO or MRO,
在两个极点上方遨游着 soar over the poles.
同时 两台机器人探测器 Meanwhile, two robot rovers
负责表层探测 explore the surface,
寻找岩石中古代水的痕迹 seeking evidence of ancient water in the rocks.
勇气号在一个高海拔 岩石满布的 Spirit is in a very highly, rocky, dusty,
崎岖不平的地方 rugged kind of place.
看探测器发回的照片就会发现 It's very sort of reddish and bright
那里有些泛红并且很明亮 when you see the picture from that rover.
机遇号在火星的另一面 Opportunity on the other side of the planet
那是个平坦 阴暗 is in a very flat place, darker,
颜色更接近巧克力棕色 more kind of chocolaty brown color
而不是红色 than a reddish color.
在2008年春季 In the spring of 2008,
探测器队伍又添新成员 the five probes are joined by a sixth.
发射 Lift off.
美国宇航局的凤凰号探测器 NASA's Phoenix Lander.
2008年5月25日 May 25, 2008.
身处地球的人们正焦急地 As anxcious men and women on Earth
注视着他们的监视器 watch their monitors,
凤凰号探测器结束了 the Phoenix Lander ends
为期九个月的太空旅程 a nine-month space journey,
以12500英里的时速 flaming through Martian atmosphere
燃烧着穿过了火星的大气层 at 12,500 miles an hour.
我们让这个宝贝飞翔 We taught that baby to fly,
我们给予它智慧 you know, we give him all the wisdom
米格尔·圣·马丁 美国宇航局/喷气推进实验室
现在 我们要放飞它 and now, we have to let it go
让它完成使命 and do the job.
火星登陆异常困难 Any landing on Mars is incredibly difficult
混沌状态就发生在6至7分钟之内 and the chaos happens within six or seven minutes,
从大气层顶端到火星表面 from the top of the atmosphere to the surface.
我们称之为 恐怖七分钟 We call it seven minutes of terror.
凤凰号必须在此时间内 That's how much time Phoenix has
把时速从12500英里降至5英里 to cut its decent speed from 12,500 miles an hour to five.
如果失败 火星 If not, Mars will
又会多一个环形山了 have one more impact crater.
多年努力终于等到了 Years of effort is being tested,
检验成果的时刻 whether it's gonna happen or not.
降落伞的展开过程 The parachute deplpoys,
被火星轨道探测器拍了下来 caught live by the Mars Reconnaissance Orbiter.
推进器使其减速 Thrusters slow the plummet
近乎完美地 for a near-perfect landing
在火星北极点附近降落 near Mars north pole.
着陆 信号检测正常 Touch down, signal detected.
凤凰号将负责搜索地表下的凝结水 Phoenix will search for frozen water under the surface,
但是 它能比预期有更多的发现吗 but it has already found more than was expected?
一幅照片中探测器的一个支架上 A phothgraph of one of lander legs
似乎有些本不该出现在那的东西 seems to show something that should not be there.
这个新证据能够证明 There is new evidence that
火星可能曾有生命存在 Mars could once have supported life.
矿床显示 Mimineral deposits show
地表曾有水流过 that water once flowed on the surface.
美国宇航局的科学家们 NASA scientists look for
在火星上寻找着任何 evidence of water wherever
能证明水寻在的证据 they can find it on Mars,
但是在2008年春 but in the spring of 2008,
他们在一个意想不到的地方 they may have found it
发现了可能的证据 in an unexpected place.
凤凰号探测器 The Phoenix Lander,
重新到达火星北极点时 newly arrived near Mars' north pole,
在它的一个支架上 has something strange
出现了一些奇怪的东西 on one of its legs.
一些同事认为那是在火星特有的 Some colleagues think that those are water droplets
环境下形成的小水滴 forming in that environment,
这有点奇怪 which is a little curious
吉姆·贝尔 康奈尔大学
因为火星上温度很低 because it's very cold.
水在那里 It's not at all obvious that
很难稳定 water should be stable there,
但它有可能是咸的 可能是海水 but it could be really salty, could be briny,
所以它的熔点更低 and so it has a lower melting point.
这是有可能的 That's possible.
我不知道在凤凰号探测器 I don't know what the blop of water on the
布鲁斯·贝茨 美国行星协会
支架上的水的构成 Phoenix Lander leg was,
或者是否有相类似的物质 or the thing that looked like that.
科学家们各抒己见 Scientists are split and
网上的博客开始大肆猜测 internet blogs run wild with speculation,
但是最后 所有都只是猜测 but in the end, it's all speculation.
不幸的是 The unfortunate thing is
我们现有的数据实在有些模糊 the data that we have are really kind of fuzzy.
我们的解决方案很有限 We're at the limit of resolution.
真是恨不得亲自上去 You really wanna go up there and
拍张更好的照片 take a much better picture of it.
这可能最终 but it may ultimately
成为一个没有答案的问题 be a question that can't be answered.
尽管到现在支架上的 Although the droplets on its leg
水滴仍是个谜 remain a mystery to this day,
当凤凰号机械手臂 when Phoenix's robot arm
在火星表面挖出2英尺后 digs two inches under the Martian surface,
证实了一个预测 it confirms a prediction,
因为它挖掘到了冻土 as it hits hard icy soil,
当中含有凝结水 containing frozen water.
火星奥德赛预测 凤凰号 Mars Odssey predicted that Phoenix would
会在少许灰尘覆盖的冻土上着陆 land on icy soil, with a little bit of dust on top.
凤凰号到达了 找到了冻土 Phoenix went, touched it.
我们得到了行星学的另一个重要部分 We got anonther key part of planetary science
即获得了实际地貌资料 which is getting "ground truth".
凤凰号团队期待发现冰水 While the Phoenix team expected water ice,
但让他们感到意外的是 they're suprised by something else that
探测器的激光探测到 the Lander's laser detects
火星的天空中有雪花 in the Martian sky: Snow.
并非固态二氧化碳 Not carbon dioxide snow,
而是水的结晶 but water crystals,
和地球上的一样 as on Earth.
火星上下雪 证明温度确实很低 It snows on Mars, which is indeed cool.
凤凰号探测到它一开始从高空大气层消散开来 Phoenix saw it first dissipating high in the atmosphere
最终落到了地面 and eventually, actually, falling to the surface
然后升华 and then sublimating
当太阳再次升起时变为气态 and going back to a gas when the sun came back up.
这是我们第一次 It really is one of the first times
真正看到地表上的大气水循环 we really seeing the surface atmosphere water cycle.
就这样 气体变为固体 In this case, gas to solid,
固体又变成气体 solid back to gas.
此外 机器人探测器也在 Meanwhile, roving robots explore
赤道附近进行探索 near the equator.
勇气号和机遇号采用高分辨率成像光谱仪 Spirit and Opportunity use high resolution imaging and spectroscopy
搜寻在火星古代时期由于水流 to find evidence of minerals and land forms,
形成的矿物和地形的资料 shaped by water in Mars' ancient past.
火星探测器的一天 A day in the life of Mars rover
从太阳升起照射到太阳能板 starts as the sun rises and illuminates the solar panels.
然后唤醒探测器开始 and wakes up the rover.
无线电指令从地球发出 The radio commads are sent from the Earth
指挥完成指令 to tell it what to do
这一次 前进10米 This time, drive 10 meters forward
然后立定转20度 and then stop and turn 20 degree.
用有色滤镜朝对应方向 and then take a panorama with these colored filters
拍一张全景图 looking off in that direction.
当天日暮时分 Near the end of the day,
美国宇航局的一颗卫星 one of the NASA orbiters,
例如火星奥德赛号 like the Mars Odyssey Orbiter,
或是火星侦察轨道器会飞过它上空 or the Mars Reconnaissance Orbiter is passing overhead
这些时间都是确定的 and we know when that's gonna happen,
机器人探测器会将当天的数据 the rover will transmit data from that day
传送到卫星上 up to that orbiter and
卫星再将信息转发回地球 then that orbiter relays it back to the Earth.
它停机时 我们已经收到它传回的 And while it's sleeping, we've got those pictures,
图像和数据 that it just sent back and other data.
现在 我们在想办法弄清楚发生了什么 And now, we're trying to figure out what happened?
它按照我们的期望工作了吗 Did it do what we're expecting it to do?
或发生了什么意外 Did it do something unexpected?
它陷入危险了吗 Is it in sosome dangerous situation?
2008年初 In early 2008,
勇气号发出的信号显示有异常出现 signals from Spirit indicate trouble
它的右前轮卡住了 its right front wheel jams.
当凤凰号团队试着让探测器往回倒时 When the Phoenix team tries driving the rover in reverse,
卡住的轮子又下陷了几英尺 the dragging wheel gouges several inches into the soil
并撞上了硅石 and hits silica.
在地球上 哪能找到硅石呢 On our own planet, where do we find silica?
热液环境 Well, hydrothermal environments.
也许火星跟地球一样 Maybe that's what we're seeing on this other world as well.
我们为此感到十分兴奋 So a lot of the excitement about
因为硅石与地球有这样的联系 silica is because of that connection to our own planet.
它表明 也许 That indicates that, hey, maybe
火星上也存在过那种环境 those kinds of environments exexisted on Mars as well.
事实上 勇气号探测器也许就停在那 In fact, the Spirit rover may be parked at one right now,
就靠近一个古老的 right next to what may have been an ancient
类似黄石地区的热区 yellowstone-like hotspot.
这是个意义非凡的意外发现 It's a classic accidental discovery,
问题也随之而来 and raises the question...
火星现在还有地下热运动吗 could Mars have current underground thermal activity?
火星内部的温度仍然很高吗 Is Mars still hot in its interior?
答案是肯定的 It certainly is.
火星不可能完全冷却下来 And there's no way that Mars has completely cooled off.
在所有的吸积热和生成热中 All the heat of its accretion, all the heat of its formation,
琳达·缇·埃尔金-坦通 麻省理工学院
一部分热量仍未消散 some of it is still there.
加上放射性元素放热 Plus, heat from radioactive elements.
火星内部绝对有充足的热量 There's definitely sufficient heat inside of Mars
使热液渗出地表 to make hot fluids percolate.
不过还是有可能 But there is that possibility
在地壳的某些深度发现液态水 没错 where you might find liquid water at some depth in the crust,yes
在黄石公园以及地球上所有的温泉中 in Yellowstone and at hot springs all over Earth,
有着种类繁多的细菌 many different species of bacteria
在沼气和富含矿物质的水体中觅食繁衍 feed and grow in the gas and mineral-rich waters.
这些不为人知的温泉 Could hidden hot springs
会是火星生命的繁衍地吗 be breeding grounds for life on Mars?
我们会向火星 We would love to send
发射电磁测深仪器 electromagnetic sounding instruments to the planet
它们能准确告诉我们 because they could actually tell us
地壳下是否有液体存在 whether there is liquid in the crust at some depth.
这真令人激动 That would be fantastic.
真相就会揭晓了 then we'd know.
当勇气号团队忙着破解火星的地下谜题时 While the Spirit team wonders about Mars' underground mysteries,
凤凰号团队在火星表面又有了惊喜发现 the Phoenix team finds another surprise on the surface.
在凤凰号探测器周围的土壤中 2% of the soil around the Phoenix lander
有2%的土壤由高氯酸盐组成 is composed of perchlorates
也就是一种氯和氧的化合物 combinations of chlorine and oxygen
在火星上发现的高氯酸盐 the discovery of perchlorates on Mars has been
劳拉·丹利 格里菲斯天文台
引起了相当大的争议 fairly controversial
因为在地球上 它可是种剧毒物质 because on Earth, it's a very toxic substance.
在地球上 高氯酸盐被用作烟花和火箭的 On Earth, perchlorates are used as propellants in fireworks
推进剂 and rockets.
这真让人惊讶 This was a surprise.
令人惊讶的发现 So it was a discovery.
为什么会有高氯酸盐 Why is it even there?
它是怎样形成的 How is it forming?
关于 高氯酸盐的问题 But the question-- perchlorates is a really
确实值得研究 而且 good question and it's not a--
目前还没有明确的答案 there's no definitive answer.
在某些地方 比如智利的阿塔卡马沙漠 Perchlorates do occur naturally
有自然生成的高氯酸盐 in places like Chile's Atacama desert
太阳发出的紫外线 as ultraviolet radiation from the sun
使氯和氧转化成高氯酸盐 transforms chlorine and oxygen.
在火星地表 应该有许多 On Mars, many of the same kinds of
相同的化学反应发生 chemical reactions might be happening on the surface.
对于地球上的这种反应 我们还没研究透彻 We don't understand the details of even on the Earth.
更别提火星上的了 let alone on Mars.
高氯酸盐带来的问题是 The challenge with perchlorates is
它们影响了一些实验的结果 they affect some of the experiments
而人们希望通过这些实验寻找 that people use to look for organics for
生命体中常见的由碳基分子构成的有机物 carbon-based molecules like you might find in life.
一些科学家开始重新考察 Some scientists are now reconsidering
1976年海盗号探测器做的著名实验 the famous 1976 experiments by the Viking lander.
1976年 海盗号在火星着陆 When Viking went to the surface in 1976,
当时人们没有发现有机物的迹象 they found no evidence whatsoever for organics.
最近流传的一个理论说 One of the recent theories that's
海盗号摄取图像
如果在火星的土壤中 being bandied about is that if you did have,
确实有高氯酸盐的话 perchlorates in the soil.
那么在进行有机物侦测 that those might have actually broken down
加热土壤样本的过程中 the organics in the same process
高氯酸盐已经将 you were using to try
有机物破坏掉了 to detect them as you heated the soil up.
高氯酸盐可能破坏了 Perchlorates may have destroyed
海盗号实验中可能存在的有机物 organic materials in the Viking experiment.
在地球上 And on Earth,
它们也是化学排放物中的主要毒素 they're a key poison in many chemical runoffs.
可高氯酸盐却是一些细菌的能量来源 But perchlorates are also power sources for certain bacteria,
这些细菌以有毒废料为食 bacteria actually used to eat toxic waste.
就生存而言 它是一把双刃剑 And in terms of life, it's a good news, bad news thing.
这些微生物能以有毒土壤为食 While microbes might feed on the toxic soil,
这些土壤对火星上的人类来说却是致命的 It could be deadly for humans on Mars.
我们不清楚这些高氯酸盐化合物 We don't know how that perchlorate compound
能否改变地表环境 might be changing the surface.
火星的地表处于高度氧化的状态 The surface might be in some kind of a super-oxidated state
最后可能会导致 比如 That could ultimately prove to be, for example,
宇航员的航天服被腐蚀 corrosive to astronaut suits.
可以确定的是 经历了5个月的探测 One thing is certain, after five months of exploration,
一股沙尘暴对凤凰号完成使命造成了威胁 Phoenix's mission is threatened by a dust storm,
它正席卷火星平原 sweeping across the Martian plains,
所到之处 皆成沙海 burying everything in its path.
在如此猛烈的风暴下 凤凰号探测器死定了 In a storm so fierce, the Phoenix lander is doomed.
美国宇航局的凤凰号探测器 When NASA's Phoenix lander
在火星上挖掘出的凝结水 digs into frozen water on Mars,
是一条新的证据 it finds new evidence
表明这个红色星球可能曾经孕育着生命 that the red planet could once have harbored life.
可在2008年的秋天 But in the autumn of 2008,
凤凰号自己的生命就要结束了 Phoenix's own life is about to end.
在火星上 风一吹过 就会卷起 On Mars, the wind comes along and whips up
像花粉粒一般的微粒尘埃 the dust, which is very, very fine-grain like flower,
吉姆·贝尔 康奈尔大学
它们都是十分微小的物质 extremely fine-grained material,
被吹到大气中 whips it up into the atmosphere and it
然后慢慢沉积下来 淹没一切 slowly settles out, blanketing everything.
红色尘埃覆盖了凤凰号探测器的太阳能板 Red dust coats the solar panels of the Phoenix lander.
日光 它唯一的能量来源 sunlight, its only source of power,
无法穿透这层尘衣 can't get through.
凤凰号探测器须花很长的时间充电 The Phoenix lander has to spend a lot of time recharging its batteries
因为夜晚温度很低 Because we know that it's gonna get very cold at night,
必须运行加热器 and it's going to have to run those heaters at night
才能保证运行 to stay alive.
2008年 11月2号 on November 2, 2008,
凤凰号最后一次关闭 再也没能启动 Phoenix shuts down for the last time.
随着火星上冬意渐浓 As the Martian winter deepens,
凤凰号探头也被干冰所冻结 frozen carbon dioxide piles up and imprisons the probe in a tomb of dry ice.
但是人们继续分析着凤凰号搜集的数据 But Phoenix's data continues to be analyzed.
到火星表面去采样 Going to Mars and taking measurements on the surface,
劳拉·丹利 格里菲斯天文台
取得更详细的化学数据 getting detailed data about chemistry of Mars
火星表面的化学成分 and Mars' chemistry of the surface
是决定其是否存在水的 was an essential piece to determining
一个重要因素 for sure that water existed on Mars.
水是生命之源 Water is essential to life.
但是根据最新的证据 But according to the latest evidence,
那仅仅只是火星形成的众多因素之一 it's only one of many forces that shaped Mars.
你可以将火星分成四个历史时期来思考 You can kinda break down our thinking of Mars now
阿什温·瓦萨瓦达 美国宇航局/喷气推进实验室
就像一场球赛分为四节一样 into maybe like four quarters of a football game.
第一个历史时期 The first quarter,
大约46至32亿年前 大量陨石聚合 from about 4.6 to 3.2 billion years ago, is action packed.
火星与其他星球一道 Mars forms along with the other planets
由气体和碎石聚合冷却形成 as swirling gas and debris combine and cool into a rocky world.
紧接着 流星撞击火星 留下疮疤 Then Mars is bombarded and scarred by meteoroids.
形成了很多坑洞 There was a lot of cratering going on.
在这段时间的末期 And then towards the end of that period,
非常多的地表特征暗示 there was a lot of geologic features that suggest
火星表层曾有过流动水存在 that there was water flowing on the surface.
新证据包含有 That new evidence includes
美国宇航局的火星侦察轨道器 this series of ridges, photographed in 2009
于2009年拍摄的一系列山脊照片 by NASA's MarsReconnaissance Orbiter.
这是第一次明确地发现火星上有湖岸 It's the first definitive lakeshore discovered on Mars,
从湖的遗迹看 其约有北美尚普兰湖大小 The remains of a lake the size of North America's Lake Champlain.
每一条关于火星上 Every piece of evidence about
水存在的证据和历史遗迹 the presence and the history of water on Mars
对于宇宙中是否 is so important
只有地球存在生命都是非常重要的 to determining whether we might be alone in the universe.
一些科学家甚至说 50亿年前 Some scientists even say 5 billion years ago,
曾有一个大西洋大小的海洋 an ocean the size of the atlantic
覆盖了1/3的火星表面 covered 1/3 of Mars.
如果有足够的时间和水源 Maybe with enough time anand enough water,
火星上也会形成生命 life formed on Mars as well.
随着火星第一个历史时期的结束 As the first quarter of Mars' history ends,
第二个时期随着一声巨响来到 the second starts with a bang.
由于火山爆发 重塑了火星 as volcanoes reshape the planet.
此时火山活动异常壮观 There was significant Volcanic activity.
火星奥林帕斯山是太阳系最大的火山 Olympus Mons is the biggest volcano in the solar system.
由此得知 过去这里存在大火山 so we know there were big volcanoes in the past.
火星被黑色火山玄武岩所覆盖 Mars is blanketed with black volcanic basalt,
就像夏威夷火山周围发现的玄武岩一样 Like the basalt found around Hawaiian volcanoes.
火山爆发释放出的化学物质 And the chemicals rereleased from volcanoes,
包含硫 并混合了水 including sulfur, mix with the water.
从而降下酸性物质 That was left and make things acidic,
就像地球上的酸雨一类的物质 kind of like acid rain on Earth and that sort of thing.
同时 大气层似乎在收缩 At the same time, the atmosphere seems to be
水资源变得越来越稀少 shrinking and water becoming more scarce
在地表也更加不稳定 and less stable on the surface.
火星大气层的稀薄 The loss of Mars' atmosphere
意味着火星地表的液态水不复存在 meant that liquid water could no longer exist on its surface.
地球水源的存在 Water exists on the surface of the Earth
艾力克斯·菲利潘科 美国加州大学伯克利分校
仅仅是因为大气压力使之降于地球表面 only because of the atmospheric pressure pushing down on it.
火星上的水要么蒸发 要么冻结 Whatever water is on Mars evaporates or freezes.
在火星的第三个历史时期 In the third quarter of its history,
氧化亚铁在沙土中锈蚀 Mars probably begins turning red from ferrous oxide.
火星逐渐变红 Rust in the dust.
在夏威夷或冰岛取一块刚形成的火山岩 take a fresh volcanic rock in Hawaii or Iceland
让它在地球大气环境中静置 and let it sit out in the Earth's atmosphere
它也会逐渐变成红色 褐色 and it's gonna turn red and brown over time.
火山岩会氧化 It's gonna oxidize.
同样的事情也可能发生在火星上 Same kind of thing could have happened on Mars.
在最后一个历史时期 In its final quarter,
火星进入了冰河时期 Mars goes into a deep freeze.
从1亿多年前到200万年前 from around 100 million until 2 million years ago,
大冰川的形成 large glaciers form
塑造了新的盆地和环形山 and carve out new patterns in basins and craters.
温暖湿润的星球变得寒冷干燥 From a warmer, wetter planet to a cold, dry world.
最新证据显示 当时火星被坚冰包裹 Mars in a nutshell, according to recent evidence.
大气层较厚 It had a thicker atmosphere.
有水 有雨 有雪 It had water, it may have had rain, it had snow.
有我们所熟知的一切 Has all kinds of things that are familiar to us.
想象一下 And it's just fascinating to think
我们能随着任务的进行 that we can go back in time with
回到早期类似地球的 these missions and study an early,
现已不复存在的火星 sort of Earth-like Mars that's now gone.
不过尽管有证据表明火星过去存在水源 But while there's strong evidence for past water on Mars,
2009年卫星照片 these 2009 satellite pictures
显示出了一些不太可能的现象 seemed to show something impossible:
火星表面存在流动的液态水 Flowing liquid water on the surface.
这可能是由于 There could be events
一直储存于地下或冻结了的水 when water that has been kept subsurface or frozen
喷涌而出 流进了陨石坑 comes gushing out and runs down the walls of these craters.
近十年最激动人心的事情 This is one of the most exciting things in the past decade
就是见到这些沟渠的照片 is seeing those pictures of the gullies,
在我的成长过程中 because when I grew up,
别人告诉我 I was taught that
火星上不可能存在液态水 there's no way liquid water could be stable on Mars today,
这有点像是对物理学的挑战 对吧 and this kind of flies in the face of the physics, right?
这让人很激动 And that's kind of exciting
因为这意味着我们可能有一些错误 because it means that we might have something wrong.
将此发现最初公布 The initial announcement of finding them,
称那是冰融化了或是含水层涌出的水之后 proposed that ice was melting or an aquifer coming up,
出现了完全不同的一套理论 there's a whole different set of theories
最新研究表明那可能来自二氧化碳 and recent study that it could be from carbon dioxide.
布鲁斯·贝茨 美国行星协会
干冰升华成气体 The dry ice going to a gas,
这种气体又起到了润滑作用 and then that gas basically doing a gas lubrication
从而使沙子流动 of the sand that's flowing down.
坦白说 And frankly,
现在仍在科学探索当中 it's still in the midst of exploratory science right now.
现在有些痕迹已被证明是沙尘流动而成 And some of these marks have been shown to be dust flows.
琳达·缇·埃尔金斯-坦顿 麻省理工学院
希望不全是这样 I hope not all of them.
我希望也有水的作用 I`d like them to be water.
从古大洋到流动的沟渠 From ancient oceans to yesterday's flowing gully,
对火星上水和生命的探索将持续下去 the search for water and life on Mars is an ongoing quest,
这就像是攀岩者选择了一条陌生的道路 a quest that like a climber's path along an unfamiliar course
途中将满布失败与曲折 is filled with false starts and unexpected detours.
这张在火星赤道附近 That's what happens when this photograph
拍摄到的照片 taken near the martian equator
让大家想起了这个 reminds a lot of people of this.
火星是否曾存在过生命 Could Mars once have supported life?
勇气号采集的矿物证据令人倍受鼓舞 Mineral evidence from probes like the Spirit rover is encouraging,
但这有可能被人借题发挥 But it can be radically over interpreted.
我们要小心仔细 And we have to be careful
不要逾越我们现有的 not to jump over a line that goes beyond
吉姆·贝尔 康奈尔大学
数据 实验和假说 what the current data, the current experiments,
可支持的范围 the current hypotheses can support.
但是很难做到不逾越 But it's hard as human beings not to just jump over that line.
2008年 许多人 In 2008, thousands
得出了一个不可思议的结论 jumped to an incredible conclusion,
当勇气号探测器拍摄的照片 when a picture taken by NASA's Spirit rover
公布到网上以后 goes viral across the internet.
这张照片看起来 Doesn't this figure look amazingly like
难道不像大脚怪吗 pictures supposedly taken of bigfoot?
这是火星上有生命存在的证据吗 Is this proof of life on Mars?
不 No.
它只是一个两英寸高的岩石 it's a two-inch tall rock.
至今我们还缺乏有力证据 We still do not have definitive evidence
艾力克斯·菲利潘科 美国加州大学伯克利分校
证明火星上存在生命 一直都没有 for the existence of life on Mars, ever.
就像19世纪的运河 Like the 19th century canals
20世纪的脸像一样 and the 20th century face
火星大脚怪就是21世纪光的把戏 the martian bigfoot is a 21st century trick of the light.
有时候人们不知道 And sometimes people don't know
如何区分事实和科幻小说 how to distinguish bebetween the facts and the science fiction.
如果火星上有或有过生命 If there is or was life on Mars,
很可能只在早期的火星 it probably evolved very early
形成过 in the planet's history,
当时火星仍然有磁场 when Mars still had a a magnetic field
可以保护它不受太空辐射的伤害 shielding it from harmful space radiation.
曾经有磁场的证据 The evidence that Mars used to
就是火星外壳的岩石 have a magnetic field lies in the crustal rocks.
绝大部分岩石凝固的时候 Most of the crustal rocks have
磁场也被封存在其中 a magnetic field frozen in when they solidify.
这些磁性岩石散布于这个红色星球上 These magnetic rocks, scattered across the red planet,
令火星有了自己的北极光 give Mars its own version of Earth's northern lights,,
就像2008年发现的那样 as discovered in 2008,
尽管这极光并非肉眼可见 although it may not register as visible light to human eyes.
在地球上 当来自太阳的带电粒子 On Earth, when charged particles from the sun
本杰明·韦斯 麻省理工学院
陷入地球的磁场线 get trapped in Earth's s field lines,
冲进大气层 smack into the atmosphere,
让大气层得到能量 they cause the atmosphere to gain energy
然后发射出一道光 and then emit a glow.
欧洲的宇宙飞船火星快车 The European spacecraft Mars Express
最近探测到了火星上的极光 recently detected aurora on Mars.
那里到底发生了什么呢 And what's s actually happening there
那里也有带电粒子涌向磁场线吗 is that there are charged particles
这些磁场线也是由 streaming down magnetic field lines
外壳剩余的磁场形成的吗 being made by remnant magnetization in the crust?
但是火星的磁场为何会消失 But how did Mars lose its magnetic field?
有种理论是 大约不到40亿年前 One theory: A little less than four billion years ago,
火星变冷的时候 as Mars cools,
其熔融铁核心凝固了 不再转动 its molten iron core solidifies and stops turning.
火星核心的运动 The motions within the core weren't sufficient
不足以产生电流来产生磁场 to generate an electric current producing a magnetic field.
但是还有一种更快的 更极端的设想 But there's also a faster, and far more violent hypothesis.
最近的另一种有争议的看法是 Another more recent idea that's pretty controversial,
火星有一个或几个像月亮一样的 is that Mars had one or more fairly large moons
大型的捕获卫星 that were actually capture satellites,
那些卫星周期性加热 and those moons tidally heated
火星的内部并维持其熔化 the interior and kept it molten,
令电流产生 allowing currents to be generated
并因此产生磁场 and thus producing magnetic field.
那么 如果火星成型后5亿年 Now, if a half a billion years after Mars's formation,
那些卫星撞向行星 those moons crashed into the planet,
就会破坏磁场 that could have destroyed the magnetic field.
大多数科学家认为 冲击理论说不通 For most scientists, the pieces of the impact theory don't fit.
首先卫星能大到足以造成如此严重的破坏吗 Could satellites large enough to do such damage
会失去足够的惯性能量而被火星捕获吗 lose enough inertial energy to be captured in the first place?
关于那些卫星在5亿年中 This idea that Mars had moons that crushed into it
撞入火星好像很不可思议 within a half of a billion of years is pretty unlikely.
但也不是完全不可能的 But it's not completely impossible.
关于火星磁场的问题 Questions about Mars' magnetic field
以及对生命的搜寻贯穿了这里 and the search for life intersect here
在火星陨石阿兰山84001中 in the martian meteorite ALH 84001
1996年 一些科学家 In 1996, some scientists
说那里面有火星细菌化石 say it contains fossilized martian microbes.
更多科学家认为那些是非生命物质 More scientists say the objects are non-biological.
从那时候起 All the time since then,
人们一直在研究这小土豆般大的陨石 people have been working on this poor little potato-sized meteorite,
布鲁斯·贝茨 美国行星协会
提取了越来越多的信息 extracting more and more information,
确实提出了一些新成果 but there's actually some new results being presented.
2010年8月 In April 2010,
研究者用新的放射性测量工具 researchers with new radiometric tools
测出早期对于这块陨石年龄的估计 announced the earlier estimates of the meteorite's age
是错误的 are wrong.
粗略估计 它的年龄 It's actually younger by
比我们想象的要小5亿年 a half billion years than we thought, roughly.
旧数据显示这块陨石出现于 The older date had placed the rock
火星正在凝固的时期 at a time when Mars was still solidifying,
也许对细菌来说都太早了 maybe too early for even microbes,
新的数据认为它 the new date places the meteorite
形成不到41亿年 at just under 4.1 billion years old.
当然 在10亿年前 That, of course, is the time, 1 billion years ago,
如果你认为火星曾适合居住的话 when, if you thought Mars was habitable,
就是在那个时候 that would be the time you would choose,
因为我们认为那时候火星表面有水流 because we think there was water flowing on the surface,,
气候更温暖 也有一个厚厚的大气层 and it was warmer. And it was a thick atmosphere.
但是来自火星的陨星 But how can a meteorite from Mars
如何来到地球的呢 end up on Earth?
来自德克萨斯达拉斯的克里斯汀娜 That was Kristina M., from Dallas, Texas,
想要"问问宇宙" wanted to "Ask the universe"
她问我们 When she texted us:
是什么使得行星的一部分 What makes part of one planet
飞离并落到另一个行星上呢 fly off and land on another?
好问题 克里斯汀娜 Great question, Kristina.
我们的确在地球上发现了 We've actually found meteorites here on Earth
确定来自于火星的陨石 that are undeniably from Mars.
已知的大约有50块 There's about 50 of them known.
我们认为 Well, what we think happens is
小行星偶然撞击了火星 that asteroids occasionally slam into Mars
将大块岩石抛进太空 and throw chunks of rock out into space
地球的重力也可以把它们拉进来 and Earth's gravity can also pull them in.
所以它们掉在这里被我们找到了 So they land here and we find them.
通过这种方法 我们确实可以 And in this way, we can actually study
在地球上研究火星碎片 pieces of Mars here on Earth.
2010年 美国宇航局宣布 In 2010, NASA announces
新陨石提示火星上存在生命
对阿兰山84001的最新电子显微镜分析 that more advanced electron microscopy of ALH 84001
发现了新的氧化铁晶体 reveals new details of iron oxide crystals,
叫做磁铁矿 called magnetite,
一种来自身具有磁场的矿石 a mineral within its own magnetic field
其在地球上可由某种海洋细菌产生的 that on Earth can be created by certain ocean-dwelling bacteria.
这种地球细菌能够 Bacteria here on Earth have figured out
琳达·缇·埃尔金斯-坦顿 麻省理工学院
在体内产生磁铁矿晶体 how to grow magnetite crystals in their own bodies
帮助它们适应地球磁场 that help them to orient to the Earth's magnetic field
使它们能在海里游泳 in order to help them swim in the ocean
在进食时进行定向 and orient while feeding.
阿兰山84001中 Are the crystals in ALH 84001
石化的磁铁矿晶体是由火星细菌产生 fossilized magnetite created by martian bacteria
就在40亿年之前 to help them hunt and feed in an ancient ocean
火星仍存在磁场时 when Mars still had its magnetic field
借此在古老的海洋觅食的吗 more than 4 billion years ago?
如果它们是化石 If they are fossils
就能说明早期火星 of course they indicate early Mars
拥有极复杂的生命体 had faily sophisticated life.
这个问题还在推敲 That's still being batted about
结果是仍然有许多 and bottom line is there's still a heck of a lot of
科学工作要做 scientific work being done
许多对火星陨石的争论 and a lot of debate about Mars' meteorites,
到底有没有任何生命存在过 whether there's any evidence past life in those.
但是最近的 最引人注目的证据 But the latest and most compelling evidence of Martian life
不在于古老的陨石中 isn't in an ancient meteorite,
而是存于现在的火星上 but on Mars today,
尽管这个新证据还未显现 even though this new evidence is invisible.
多年来 科学家们在火星上寻找生命 For years, scientists looking for life on Mars
一直追寻着水 have followed the water,
但是接下来还有点 but there may be something to follow,
更令人激动的事情 that's even more dramatic.
1999到2009年间 Between 1999 and 2009,
对火星的光谱观测 spectrographic observations of Mars
探测到了一种碳氢结合物 detect a combination of carbon and hydrogen
叫做甲烷气 called methane gas.
在火星大气层中发现甲烷 The discovery of methane on Mars, in Mars' atmosphere,
阿希文·瓦萨瓦达 美国宇航局/喷气推进实验室
实在令人吃惊 was a real surprise to people.
气体烟雾似乎是在夏季 Plumes of the gas seem to be coming
从火星的几个热点冒出来 from a few "Hot spots" during the Martian summer.
令人费解的是火星上本不该存在甲烷 The trouble is there shouldn't t be any methane on Mars.
在火星上 即便是甲烷的出现 On Mars, even just the presence of methane,,
吉姆·贝尔 康奈尔大学
都有些神秘 因为它会分解 is a little bit mysterious because it breaks down.
地球上 不稳定的甲烷分子 On Earth, the unstable methane molecule
经过约300年就会分解 disintegrates after about 300 years.
而在火星上 受到大量的紫外线辐射 But on Mars, high doses of ultraviolet radiation
以及新近发现的干闪电的影响 and perhaps the newly discovered dry lightning
在火星稀薄而尘霾的大气内 in the thin, dusty Martian atmosphere
或许只需数月就能让甲烷完全解体 break the methane down in just a few months.
因此 如果甲烷存在的话 And so if you see it there,
意味着一定也存在某种供源 it means there must be something resupplying it.
因此即使它不断分解 Even though it's being broken down,
也还有源源不断的供给 it's getting resupplied.
火星甲烷究竟来自何方 Where's the Martian methane coming from?
地球上 火山活动产生大量的甲烷 On Earth, volcanoes produce vast amounts of methane.
然而即使火星上有奥林帕斯山 But even though Mars has Olympus Mons,
这座太阳系内最大型的火山 the largest volcano in the solar system,
也有数百万年不曾喷发了 it hasn't t erupted for millions of years.
还有其它选项吗 So what are the other choices?
甲烷也可以来自地下 Methane can be produced underground
当玄武岩转化为蛇纹岩 when basaltic rock gets turned into a mineral called serpentine.
会释放甲烷 and that releases methane
甲烷慢慢渗出地表 And that methane can seep up through the ground,
进入大气 and come out in the atmosphere.
然而该过程需要高温液态水的存在 But this process requires hot liquid water
这在火星表面及内部尚未发现 which hasn't yet been found on or within Mars.
在火星上是否有我们至今未知的 Could be volcanoes which we don't
活火山存在呢 这就很有趣 know to be active on Mars, so that would be interesting.
布鲁斯·贝茨 美国行星协会
也可能是火星地下我们未知的 It could be some subsurface chemistry with liquid water,
某种含液态水的化学物质 which we don't t know to be on Mars,
这也很有意思 so it'd be interesting.
还可能就是源于微生物 Or it could be due to biology.
地球上 90%的甲烷 On Earth, 90% of methane
源于动植物体内的细菌 comes from bacteria in animals and plants.
那么火星的甲烷是否 Is the Martian methane coming from
就来自地底的细菌菌落呢 underground colonies of bacteria?
火星上有甲烷的消息登上报纸头条 The discovery of methane on Mars led to headlines
成为发现火星生命存在的决定性证据 of us having definitively found evidence for life on Mars.
人们建了许多聊天室 And entire chat rooms were set up
艾力克斯·菲利潘科 美国加州大学伯克利分校
讨论各种火星生物 然而事实上 to discuss these various creatures, but in fact,
尽管甲烷的发现非常有趣 though the discovery of methane is interesting,
但这并不意味着 it doesn't mean that
美国宇航局称 火星上的甲烷意味着可能存在生命
我们在火星上发现了四处游荡的生物 we found creatures wandering around on Mars.
或许的确存在生命体 Maybe it is life.
琳达·缇·埃尔金斯-坦顿 麻省理工学院
我们对未知只有一步之遥 It's an arrow to something and
或许一步之遥外的未知就是生命 maybe the thing at the end of the arrow is life.
探查火星甲烷来源 The search for the source of Martian methane
成为探索者们的当务之急 has become a priority for explorers
也是即将发射的火星登陆探测器任务之一 and is on the mission list for the next rover to be sent to Mars.
现在我们看到的是所谓的测试床版的 So we're looking at a so-called test bed version,,
火星科学实验室探测器 of the Mars science laboratory rover.
当火星科学实验室 And the Mars science laboratory,
在地表着陆后 会检测甲烷 when it gets down to the surface, will measure methane.
探测器到达后一切都会真相大白 So we'll know the answer once that rover gets down there.
被称为"好奇者"的火星科学实验室 The Mars science laboratory dubbed "Curiosity"
将于2011年秋发射 2012年着陆 will launch in the fall of 2011, and land in 2012.
它的身形如小型汽车 It's the size of a small car
会以一种不可思议的新技术进行着陆 and will use an amazing new landing technique,
称为空中起重机 the sky crane.
在离地面60英尺时 At about 60 feet above the ground,
探测器与着陆架分离 the rover is separated from the descent stage
由缰索束缚直线下降 and lowered on a line, which we call the bridle,
斯蒂芬·李 美国宇航局/喷气推进实验室
并缓慢地降至地面 and slowly lowered to the ground anand lowered to the ground.
当探测器四轮着地 When the rover's wheels touch down on the ground,
着陆架收到反馈信息 the descent stage detects that.
它将缆索切断并飞向远方 It cuts those lines and then it flies away
在安全距离之外坠毁 and it crashes safely far away
探测器就四平八稳到达地表 and the rover is on the ground, on its wheels,
随时准备开展工作 ready to go do its job.
高频雷达是空中起重机式着陆的关键 The high-frequency radar, essential to ththe sky crane landing,
现正安装在直升机上进行实际测试 is mounted to a helicopter and taken for a test-drive
地点就在加州爱德华兹空军基地 at California's Edwards air force base.
说到火星着陆时 When you're coming down on Mars,
对于下降角度 we don't watch a simulation and analysis
詹姆斯·蒙哥马利 美国宇航局/喷气推进实验室
及降落伞的姿态角速度等 to go ahead and give us bounds of what we expect to see
我们无法通过模拟和分析 in terms of descent angles,
得出我们期待的边界范围 in terms of attitude rates on the parachute.
在进入 下降和着陆的过程中 During the entry, descent, and landing,
雷达会反馈地面位置 the radar tells us where the ground is
以及飞行器行进的速度 and how fast we're going.
控制系统用这些信息 That information is used by the control system
确保推进器着陆时能稳稳当当 to control the thrusters to make sure we touch down at a nice gentle speed.
我们将各个部分进行了仔细测试 We test little pieces here and little pieces there,
米格尔·圣·马丁 美国宇航局/喷气推进实验室
而首次真正的考验就在火星 so the first time that we test it for real is on Mars.
火星实验室的首要目标 The key objective of the Mars science laboratory
是搜寻远古生物栖息地存在的迹象 is to search for signs of ancient habitats.
探测器会不断地来回勘查 And so the rover will rove up to areas that had
一度水盈土润的那些区域 been soaked in water in the past,
以期找到残存的有机物 and it may have trapped organics.
如果我们能找到这类地层 So if we find those kind of layers,
就能深入地层中的岩石 we can go up to that kind of a rock ,
钻探并提取岩石内的物质 and we can drill into it and take the material from inside the rock
就能更精确地得出岩石的成分 and tell with a lot of precision what the rock is composed of,
看其中是否存在有机物质 whether there's s organics in there.
火星实验室同时也是研究 The Mars science laboratory will be one more link,
夜空中 in a chain of exploration
大红斑现象的重要一环 to understand that bright red dot in the dark night sky.
拢合起新的证据 Put together all the new evidence
结果却需要更多的证据 and it adds up to the need for more evidence.
我们不知道磁场是如何消失的 We don't t know how the magnetic field was lost.
我们不清楚大气层是如何消失的 We don't t know exactly how the atmosphere was lost.
我们不知道水都到哪里去了 We don't know where all the water went.
我们不知道甲烷的来源究竟是生命体 We don't know whether the methane is produced by life
还是非生命物质的化学反应 or just regular abiotic chemical reactions.
或许19至20世纪令人大惑不解的谜团 But maybe questions that baffled the 19th and 20th centuries,
将在21世纪豁然开朗 WILL BE ANSWERED IN THE 21st.
我问其他5位火星科学家 I asked five other Mars scientists:
你们认为火星上曾存在生命的 what percentage chance would each of you give
概率有多大 that life ever formed on Mars?
我们有4人认为有超过90%可能性 Four of us thought it was maybe greater than 90% chance,
火星过去曾经 甚至现在就存在生命 that there had been at some time and maybe now life on Mars.
而另外2人则认为不足15% And two of us thought it was less than 15%.
接下来的问题就是 如果你认为 And the follow-on question then is, if you think that
只有低于15%的可能性 there's a less than 15% chance,
是否还值得如此煞费苦心的探求呢 is it really worth going to look for it?
我会毫不迟疑地回答 绝对肯定 And the answer was immediately, Absolutely.
我认为探测器和人造卫星等 I don't think that rovers and landers and orbiters
在火星上找不到生命 are gonna find life on Mars.
我认为这必须靠人类 My personal opinion, I think it's gonna take people.
有朝一日 人类会登陆火星 I think there will come a day when people go to Mars
挖掘 钻探 和思考 digging and drilling and thinking
身入其境 顺理成章 and just going with context and gut feel
逐一破解这个复杂难懂的谜题 and putting the pieces of a very complicated puzzle together.
我很乐观 I'm optimistic
相信必定会找到曾经存在生命的证据 that we're gonna find evidence of past life.