This is a picture of a sunset on Mars taken by NASA's Curiosity rover in 2013. Mars is a very cold planet, flooded with high levels of UV radiation and extremely dry. In fact, Mars is considered to be too dry for life as we know it.
﻿这是一张由美国宇航局 好奇号探测器 在2013年拍摄的火星上的日落图。 火星是一个非常寒冷的星球， 被高强度的紫外线所覆盖， 并且极度干旱。 事实上，我们认为火星上过于干燥， 根本不适合物种的生存。
I'm an astrobiologist. I try to understand the origin of life on Earth and the possibilities of finding life elsewhere in the universe. People sometimes ask me, how can you be an astrobiologist if you don't have your own spaceship?
我是一个天体生物学家。 我试图了解地球上生命的起源， 以及在宇宙中其它地方 找到生命的可能性。 人们有时问我 你都没有自己的宇宙飞船， 怎么能做一个天体生物学家呢？
Well, what I do is that I study life in those environments on Earth that most closely resemble other interesting places in the universe. All life on Earth requires water, so in my case I focus on the intimate relationship between water and life in order to understand if we could find life in a planet as dry as Mars. But since I do not have the 2.5 billion dollars to send my own robot to Mars, I study the most Martian place on Earth, the Atacama Desert.
事实上，我所做的是研究地球上 那些跟宇宙中其它一些有趣的地方 非常类似的环境中的生命。 地球上所有的生命都需要水， 所以就我而言，我专注于研究 水和生命之间的密切关系， 以便去了解 我们是否能在一个像火星 这样干燥的星球上发现生命。 但是由于我没有发送机器人去火星 所需的25亿美元， 所以我只能研究地球上 最像火星的地方， 也就是阿塔卡马沙漠。
Located in northern Chile, it is the oldest and driest desert on Earth. To give you an idea of how dry it is, consider here in Vancouver it rains over 1,000 millimeters of rain every year. In the Atacama, there are places with no reported rains in the last 400 years.
它位于智利北部， 是地球上最古老、最干燥的沙漠。 为了让你了解它有多干燥， 对比一下，温哥华 每年降雨超过1000毫米。 而在阿塔卡马， 有些地方在过去400年 都没有降水的报道。
How do I know this? Well, because I was born and raised in the Atacama --
我是怎么知道的呢？ 因为我出生并成长在阿塔卡马——
(Laughter)
（笑声）
So I had a unique advantage when I started studying this desert. So let me tell you guys a few fantastic examples he has found on how life has adapted to live with almost no water at all.
所以当我开始研究这片沙漠时， 就已经具备了独特的优势。 让我来告诉你们一些我所发现的， 关于生命是如何 在几乎完全无水的环境中 适应并生存的奇妙事例。
One of my first findings was in the entrance of a cave facing the Pacific Ocean. In this place, we reported a new type of microalgae that grew only on top of the spiderwebs that covered the cave entrance. Have you ever seen a spiderweb early in the morning? It's covered with dew, so this microalgae learned that in order to carry photosynthesis in the coast of the driest desert on Earth, they could use the spiderwebs. So here they may access the water from the fogs that regularly cover these areas in the morning.
我最初的发现之一是在一个 面向太平洋的洞穴入口处。 在这里，我们发现了一种新的微藻， 它只生长在布满了 洞穴入口的蜘蛛网上。 你见过早上的蜘蛛网吗？ 上面沾着露水， 所以这种微藻学会了 要想在这个 地球上最干燥的沙漠的边缘 进行光合作用， 它可以利用蜘蛛网。 在这里它们可以从 经常在早上 覆盖这些区域的浓雾中获得水份。
In another cave, we found a different type of microalgae. This one is able to use ocean mist as a source of water, and strikingly lives in the very bottom of a cave, so it has adapted to live with less than 0.1 percent of the amount of light that regular plants need. These type of findings suggest to me that on Mars, we may find even photosynthetic life inside caves. And by the way, that's me.
在另一个洞穴中， 我们发现了一种不同的微藻。 这种微藻可以利用海雾作为水源， 并且显然是生活在洞穴的底部， 所以它适应了在 光照不到普通植物 所需光照量的0.1%的环境下生活。 这类发现提醒了我在火星上， 我们也可能在洞穴中 发现依赖光合作用的生物。 顺便说一下，照片里那个是我。
(Laughter)
（笑声）
Now, for almost 15 years this region of Yungay, discovered by NASA, was thought to be the driest place of this desert, but I knew that it was not. How? You already know the answer. Because I was born and raised in this desert. So I remembered that I usually see fogs in Yungay, so after setting sensors in a number of places, where I remember never seeing fogs or clouds, I reported four other sites much drier than Yungay, with this one, María Elena South, being the truly driest place on Earth, as dry as Mars, and amazingly, just a 15-minute ride from the small mining town where I was born.
在过去的将近15年里， 这个被美国宇航局发现的云盖地区， 被认为是这个沙漠中最干燥的地方。 但是我知道它不是。 我是如何知道的呢？ 你们已经知道答案了。 因为我出生并成长在这个沙漠。 我记得我经常在云盖看到雾气， 所以在好几个我记得从来没见过 雾或云的地方放置传感器后， 我发现了四个比云盖更干燥的地方， 这个地方，玛丽亚-埃伦娜南部， 是真正的，地球上最干燥的地方， 就像火星上一样干燥， 让人意想不到的是， 这里离我出生的 矿业小镇只有15分钟的车程。
Now, in this search, we were trying to actually find the dry limit for life on Earth, a place so dry that nothing was able to survive in it. But even here, well hidden underground, we found a number of different microorganisms, which suggested to me that similarly dry places, like Mars, may be inhabited. We even have some preliminary evidences that these microorganisms may still be active in the desiccated state, like walking mummies all around us, and that they may be using UV radiation as a source of energy. If confirmed, this would have a huge impact on our definition of life, on how we look for life elsewhere in the universe.
在这项研究中，我们尝试着去找到 地球上的生物忍受干旱的极限， 去找到一个干燥到 没有任何生命能够存活的地方。 但是即便是在这里，在隐藏的地下 我们还是发现了一些不同的微生物， 这意味着在类似的干燥地区， 比如火星上， 可能是有生命存在的。 我们甚至有一些初步的证据， 证明这些微生物在脱水的情况下 仍然能够活动。 就像是在我们周围行走的木乃伊， 并且它们可能将紫外线作为能源。 如果被证实了， 这将对我们如何定义生命， 以及如何在宇宙中的其它地方 寻找生命产生重大的影响。
Due to its clear skies, by 2020, 60 percent of the biggest telescopes on Earth will be located in the Atacama, and while everyone else will be looking among the stars to answer the question, "Are we alone?" I will be looking down to the ground searching for this same answer in my own backyard.
得益于它晴朗的天空，到2020年， 地球上60%的大型天文望远镜 将会被安装在阿塔卡马， 在每个人都将抬头望向星空去寻找 “我们独自存在于宇宙中吗？” 这个问题的答案时， 我则会望向地面， 在我的后院 寻找同一个问题的答案。
Thank you.
谢谢。
(Applause)
（掌声）