1 00:00:00,000 --> 00:00:16,345 In 1995, NASA’s Hubble Space Telescope spent 10 days looking at a seemingly empty pinpoint in the sky. 2 00:00:16,345 --> 00:00:23,189 Instead of darkness, what Hubble found changed our understanding of the universe... 3 00:00:23,189 --> 00:00:30,864 The Hubble Space Telescope is an outstanding  time machine, in a sense, because of course in   4 00:00:30,864 --> 00:00:37,328 astronomy anything we look at in space we're  seeing it as it was when the light from that   5 00:00:37,328 --> 00:00:42,459 object, be it a planet, a star, or  a galaxy began its journey to us.   6 00:00:42,459 --> 00:00:48,298 Now, normally we don't really think about  that when we're just looking at the night sky,   7 00:00:48,298 --> 00:00:53,511 but it's incredibly important for our studies  with the Hubble Space Telescope to realize that   8 00:00:53,511 --> 00:00:59,350 when we're looking at a galaxy, we're  seeing it as it was millions of years   9 00:00:59,350 --> 00:01:07,942 ago, sometimes billions of years ago. It's  taken that long for the light to get to us. 10 00:01:07,942 --> 00:01:23,122 In 2004, the Hubble Ultra Deep Field revealed over 3 times more galaxies than the Hubble Deep Field. 11 00:01:23,122 --> 00:01:36,846 Further Hubble deep fields have shown us that there are hundreds of billions of galaxies in the universe. 12 00:01:36,846 --> 00:01:41,518 One of the neat things about the Hubble Ultra Deep  field, and one of the things that made it so unique   13 00:01:41,518 --> 00:01:46,523 was how long it took us to take that image. There's  an exposure time that's expressed, I think it's   14 00:01:46,523 --> 00:01:53,029 11.2 days, it's a very, very long exposure time. But  probably what's more important is how many orbits   15 00:01:53,029 --> 00:02:00,787 it took us to do that. 400 orbits of Hubble data  to take that image, that's a lot of orbits! It was   16 00:02:00,787 --> 00:02:06,960 a lot of Hubble time, you only get 15 orbits a day,  to take 400 orbits and say we're going to observe   17 00:02:06,960 --> 00:02:12,465 this one spot in the sky for 400 orbits, and I  think the results from the science, I mean it was   18 00:02:12,465 --> 00:02:16,052 amazing, what they saw was spectacular. 19 00:02:16,052 --> 00:02:19,722 We see some of the faintest objects showing up in these images   20 00:02:19,722 --> 00:02:27,105 and those faint objects are often distant galaxies.  These deep fields have revealed visually to us   21 00:02:27,105 --> 00:02:33,361 a universe absolutely teeming with galaxies,  hundreds of billions of galaxies. In one deep   22 00:02:33,361 --> 00:02:39,576 field alone we can see a thousand of these little  smudges of light which are distant galaxies.   23 00:02:39,576 --> 00:02:46,708 By doing that we can compare galaxies that are  shining to us from billions of light years away   24 00:02:46,708 --> 00:02:53,173 with galaxies closer to us, or even to our own  Milky Way and see if they're similar or different.   25 00:02:53,173 --> 00:03:01,222 What Hubble has revealed is that the universe  has in fact changed over these billions of years of time. 26 00:03:01,222 --> 00:03:06,227 We looked at the darkest part  of the sky, very small part of that, and we   27 00:03:06,227 --> 00:03:12,233 were amazed at how many galaxies we found. And we  continued to go back to that portion of the sky   28 00:03:12,233 --> 00:03:21,659 to even increase that visibility, and we've seen  tens of thousands of galaxies, just it's amazing.   29 00:03:21,659 --> 00:03:25,496 Hubble spent two weeks taking  pictures of empty places in the sky,   30 00:03:25,496 --> 00:03:29,500 and they saw they weren't empty at all there were  thousands and thousands of galaxies. In astronomy,   31 00:03:29,500 --> 00:03:33,755 there's what we knew before Hubble and now there's  what we know after Hubble, they're so different.   32 00:03:33,755 --> 00:03:37,175 Basically every page of an astronomy textbook now  33 00:03:37,175 --> 00:03:41,512 says something about discoveries made with Hubble, every page. 34 00:03:41,512 --> 00:03:46,601 Hubble has given us this picture of the  universe evolving over billions of years of time   35 00:03:46,601 --> 00:03:54,067 into a place where now we have galaxies with  plenty of stars and interesting chemical makeup,   36 00:03:54,067 --> 00:04:01,241 so this is something that I'm grateful to the  Hubble Space Telescope for opening our eyes to. 37 00:04:01,241 --> 00:04:18,007 [ MUSIC ]