这表明，地球上的水可能来自内部，由于地质活动，被带到表面形成海洋。
This suggests that Earth's water may have come from inside, driven to the surface to form the oceans, by geological activity.
现在主流的学者认为，地球上的水来自彗星撞击后的沉淀物。
Until rather recently, the prevailing wisdom has been that Earth's water supply was primarily deposited by comets.
小行星的冰可能是地球上的水是从哪里来的这一难题最好的答案。
This ice on asteroids may be the answer to the puzzle of where Earth's water came from.
地球上的水处于自然大循环和社会小循环交织成的往复循环运动之中。
Water on the earth is in constant motion between the great natural cycle and small social cycle.
有趣的是，泰坦上的甲烷和地球上的水很相似，也能成云降雨并带来风暴。
And interestingly, Titan's methane is a lot like water: it forms clouds in the atmosphere and falls in showers of raindrops, occasionally producing storms.
我们应当采取措施来保护地球上的水。否则，最后一滴水将是我们的眼泪。
We should do something to protect the water on the earth. Otherwise the last drop will be our tears.
上周这一理论取得了重大进展，随着科学家发现至少部分彗星和地球上的水相同的化学特性。
That idea got a big boost last week with the discovery that some comets, at least, have the same chemical signature as the water found on Earth.
反观地球上的水则是一直在反复搬运著数量庞大的沉积物，那么在火星上也可能进行相同的过程。
Flowing water, though, has routinely moved gargantuan amounts of sediment on Earth and could have done so on the Red Planet as well.
研究人员通过研究宇航员从月球上带回的岩石发现月球上那少得可怜的水其化学成分跟地球上的水不同的。
Researchers studying rocks brought back by astronauts have found that the moon's scarce water has a different chemical signature than Earth water.
有理论认为地球上的水可能是由其它小行星以冰的形态运送而来，如今的这一发现为该理论提供了有力佐证。
The find provides support for the theory that Earth's water could have been delivered as ice by an asteroid.
地球外表的70%被水掩盖着，那边是依然用尽水的世界的很多中央。因而我们应该使在地球上的水用得好。
About 70 percent of the earth's surface is covered with water, there are many places in the world still running out of water.
他们发现，同地球上的水相比，氘的含量更高——但同海尔·波普彗星、哈库塔克彗星和哈雷上的水有着相似的平。
They found deuterium at higher levels than it's found in Earth water - but at levels similar to the comets Hale-Bopp, Hyakutake and Halley.
他们发现，同地球上的水相比，氘的含量更高——但同海尔·波普彗星、哈库塔克彗星和哈雷上的水有着相似的平。
They found deuterium at higher levels than it's found in Earth water —but at levels similar to the comets Hale-Bopp, Hyakutake and Halley.
促使月球上的水与地球上的水不同的是月球含有水的成分- - - - - -氢和氧- - - - - -但是还不是水。
What makes the water on the moon different from water on Earth is that it contains the ingredients for water - hydrogen and oxygen - but is not yet water.
国家地理还很慷慨的分享了15幅图片，与新闻机构以及美国国家航天局提供的照片组成了一个作品集——都是和我们的家，地球上的水有关的。
National Geographic was also kind enough to share 15 of their images below, in a collection with other photos from news agencies and NASA - all of water, here at home - Earth. (43 photos total)
有趣的是，至少在地球上它需要强酸性的水来形成。
The interesting thing is that on Earth at least it needs highly acidic water to form.
地球上早期的生命形式被限制在海洋里，因为水是帮助它们抵御紫外线辐射的唯一有效保护。
Early life-forms on Earth were confined to the oceans because water was the only available protection they had against ultraviolet radiation.
它被称为“明亮的早期的太阳解决方案”，根据该方案，太阳将提供足够的热量，使地球和火星上的水变成液体。
It is called the bright-young-Sun solution, according to which the Sun would have provided enough heat for the water on Earth and Mars to be liquid.
我们讨论了30到40亿年前地球和火星上液态水存在的地质证据。
We were discussing the geological evidence of liquid water on Earth and Mars three to four billion years ago.
通过观察存在于极端环境下的生物，研究人员发现液态水只能在有限范围内的温度和压力下供生物使用这些发现会让科学家对外太空生命的搜寻集中到太阳系来。 莱恩威弗说：“我们猜想在地球上找到的这些限制条件是限制所有以水为支撑的生命的基础。”
After compiling observations of life in extreme environments, the researchers found that liquid water in only a limited range of temperatures and pressures can support life.
水是一个是否有生命存在的关键问题，即使是以微生物的形式，火星上和地球上都曾经存在，所有已知的生命都需要水。
Water is a key to the question of whether life, even in the form of microbes, ever existed on Mars. On Earth, all known forms of life require water.
她给了地球上所有生物生命，给我们提供生活所必需的空气、食物、水和一切基本的需要。
She gives life to all the living things on the earth and provides us with air, food, water and other essential things we need for living.
科学家把地球上可饮用的淡水——包括湖泊、河流和蓄水层的水统称为“深海”，人类每一年能够使用大约三分之一的“深海”。
Of all the fresh water accessible in lakes, rivers and aquifers — what scientists call “blue water” — humankind uses about one-third every year.
发现潜在的水资源显然对这个计划大有助益，特别是有可能为宇航员提供水库以资使用，而无需依靠从地球上运水。
Discovering a potential water supply has obvious benefits for that scheme, not least providing astronauts with a potential reservoir that they can tap into rather than rely on shipments from Earth.
发现潜在的水资源显然对这个计划大有助益，特别是有可能为宇航员提供水库以资使用，而无需依靠从地球上运水。
Discovering a potential water supply has obvious benefits for that scheme, not least providing astronauts with a potential reservoir that they can tap into rather than rely on shipments from Earth.
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