这使人们确信天文周期已经存在了数十亿年。
It assures that the astronomical cycles have been in existence for billions of years.
在数十亿年的时间里，这些气体被引力压缩成星系、恒星、植物，最终甚至变成了人类。
Over billions of years, the gas was compressed by gravity into galaxies, stars, plants and eventually, even humans.
由于我们这样的行星的寿命是几十亿年，我们可以预测，如果我们星系中有其他生物生存，它们的年龄将从零到几十亿岁不等。
Since the lifetime of a planet like ours is several billion years, we can expect that, if other civilisations do survive in our galaxy, their ages will range from zero to several billion years.
不过只是三年前，但是感觉好像已经过了几十亿年。
It WAS only three years ago, but it feels as though aeons have passed.
构成这些生命所必需的元素需要几十亿年的时间。
Building up the elements needed for life this way takes billions of years.
数据储存数十亿年的愿景令人着迷却又有点可怕。
The prospect of billion-year storage is fascinating and a little terrifying.
数十亿年过去，会合最终可能导致它们合并成一个星系。
Drawn out over billions of years, the encounters will likely result in their merger into a single galaxy of stars.
具有代表性的是，构成行星状星云的恒星已经存活了十亿年。
Stars that form planetary nebulae typically live for billions of years.
数十亿年以来，环境以及对基因的影响一直是生物体进化的关键。
For billions of years, the environment and how it affected organisms' genes was the key to evolution.
海洋机构开始和包括孩子在内的人们签订十亿年服务期限的合同。
Sea Org initiates-some of whom are children-sign contracts for up to a billion years of service.
矮星系之间的如此遭遇通常发生在几十亿光年之外，也就是几十亿年之前。
Such encounters between dwarf galaxies are normally seen billions of light-years away and therefore occurred billions of years ago.
十亿年以后，你们就已经消耗完,所有的旋转动能,然后地球就不会再旋转。
then, you would have consumed up all the rotational kinetic energy and then the earth would no longer be rotating.
如果新的生物域属实，那么它存在已达几十亿年之久，因此必有值得研究的地方。
If the new domain is real, it must have been around for several billion years, and must thus have something going for it.
科学家们是在分析检验了在数十亿年之前坠落到地球上的陨石之后得出这一发现的。
Scientists have analysed meteorites that formed billions of years ago before falling to Earth.
在地球上搜寻外星人工物品：地球已经存在了几十亿年，谁能说外星人过去未曾来过呢？
Look for an alien artifact here on Earth: Earth has been around for billions of years-who says that aliens haven't been here before?
虽然它们中有些元素发生衰变(平均)要历经数十亿年，地球的存在也只有数十亿年历史！
Even though some of these elements take billions of years to decay (on average), the Earth has been around for billions of years!
这张惊人美丽的深景照片显示，这两个庞大星系的引力战斗难分难解，一如过去的十亿年。
This stunning vista shows these two mammoth galaxies locked in gravitational combat, as they have been for the past billion years.
数十亿年以来，某些细菌和真菌通过产生化学物质来保护自己，抵御来自其它微生物的攻击。
For billions of years, certain bacteria and fungi have produced chemical substances to protect them from attack from other microorganisms.
如果你需要钻石，那你可以去找珠宝商，或者把碳深深埋入地下，让它在那里带上几十亿年。
Say you need a diamond. You could go down to the jeweler or you could put some carbon deep underground and let it sit for a couple billion years.
它也是为了揭示细菌这种无父无母的生命形式，为何能主宰地球数十亿年，而且至今还欣欣向荣。
It is also explaining why the life forms that ruled the planet for billions of years and remain by far the most abundant - the bacteria - manage fine without it.
我们现在的氦源，是地下天然气田中放射元素衰变的副产品，经过数十亿年的累积，逐渐形成的。
Our modern supply of helium has gradually built up over billions of years in subterranean pockets of natural gas as a byproduct of decaying radioactive elements.
随后，河槽逐渐干涸，风吹着大地，侵蚀地面，数百万年，甚至几十亿年，河槽退化为山脊形状。
Subsequently they dried up and wind eroded the ground around the channels over millions, maybe even billions, of years, leaving the more resistant channel rocks as ridges.
研究人员推测数这些碎块经过数十亿年的互相碰撞，柯伊伯型天体磨得更碎，柯伊伯带原始状态不再。
Researchers surmise that over billions of years the debris should collide, grinding the KBO-type objects down to ever smaller pieces that were not part of the original Kuiper Belt population.
历经数十亿年，生物体已经进化出种类繁多的手段，以求得在这个不断变化的地球上生存、成长和繁衍。
Over billions of years, organisms have evolved an enormous variety of methods to survive, grow and proliferate on a continually changing planet.
再过五十亿年，它将膨胀成一颗红巨星，到时就算我们的地球不被它吞并，行星表面也将被烤成混凝土。
In another 5 billion years it will swell into a red giant and either consume our planet or bake its surface to concrete.
但在这持续十亿年的事件中，两个编号为NGC 4038和NGC 4039的星系中的恒星没有相撞。
But the stars in the two galaxies cataloged as NGC 4038 and NGC 4039 don't collide in the course of the ponderous, billion year or so long event.
但在这持续十亿年的事件中，两个编号为NGC 4038和NGC 4039的星系中的恒星没有相撞。
But the stars in the two galaxies cataloged as NGC 4038 and NGC 4039 don't collide in the course of the ponderous, billion year or so long event.
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