We estimate that there are hundreds of billions of galaxies in the universe,

我们估计宇宙中应该有数百亿个星系，

but its only until you see that Hubble Deep Field, and you understand you are seeing a tiny little patch of sky and yet it is filled to the brim with galaxies.

在看过“哈勃深度区”后，你会明白我们所看到的只是太空中的一小块，即便如此，它也被星系塞的满满的。

And that's telling you that this universe is an astonishing and crowded and wonderful place.

这告诉你，我们的宇宙是个令人惊异的、拥挤的、奇妙的地方。

The entire history of growth and change in galaxies is written in this single image of the Hubble Deep Field.

关于星系成长、变化的整部历史都收录在“哈勃深度区”的一张图片上。

What may be Hubble's most profound discovery cannot be seen at all, by any means.

可能成为哈勃意义最为深远的发现，无论如何用肉眼是看不到的。

Something with so much power, it holds the entire universe together.

某种东西能量奇大，能让整个宇宙保持聚集状态。

For a number of years, astronomers like Kim Weaver have been surprised by the way galaxies behave.

数年来，像金·威弗一样的天文学家对星系运行的方式感到惊讶。

Our observations of things we could see, like galaxies, weren't making a lot of sense to us.

我们观测到的像星系这样可见的东西对我们意义不大。

For example, how a galaxy rotates.

比如，星系是如何旋转的。

The arms of spiral galaxies seem to move faster than the laws of physics would allow.

旋状星系的旋臂运行的速度似乎比用物理法则算出的速度快。

Astronomers spotted other oddities as well.

天文学家还观测到了一些奇异的其它事情。

You can have clusters of galaxies that have hundreds to thousands galaxies in them.

你能看到星系簇中有数百至数千个星系。

These clusters of galaxies are still bound to each other.

星系簇始终能让星系束缚在一起。

The galaxies are still orbiting after all this time.

这些星系历经许久，始终在它们初始轨道上运行。

Why are they bound to the cluster·

它们为什么会被束缚在星系簇上·

There's something there creating gravity, creating the bending of space to hold these galaxies in place and to hold galaxies in their rotation that we are not seeing.

一定有什么东西在制造引力，在弯曲空间，以此让星系保持在原来位置，保持星系做出我们看不见的自转运动。

Astronomers hypothesize that galaxies are surrounded by a halo of unknown forms of matter.

天文学家做出假设，星系被不知名的物质构成的圆圈所包围着。

This matter acts like a glue that holds the universe together.

这种物质像胶水一样把宇宙聚集在一起。

They call it, Dark Matter.

天文学家将其称做“黑暗物质”。

Though we can't see Dark Matter one astronomer has discovered a way to find it.

虽然我们看不见黑暗物质，但一位天文学家想出了一个办法找出它。

We took the Hubble Space Telescope and over two years, slowly pieced together a mosaic of 600 images tiled together, a large patch of sky in which we could see about 2 million faint galaxies.

我们用哈勃望远镜观测了2年，慢慢的将600张图拼凑在一起，他们拼出了太空中的一大块区域，在其中我们能看到大概2百万个星系。

And this was the Hubble Space Telescope Cosmos Survey The largest ever survey taken from space.

这是哈勃太空望远镜有史以来最大的太空勘查。