0:00:27.060,0:00:28.060 In all of time 0:00:32.020,0:00:33.060 on all the planets of 0:00:33.560,0:00:34.880 all the galaxies in space 0:00:39.660,0:00:41.660 what civilizations have risen, 0:00:44.480,0:00:45.920 looked into the night 0:00:50.240,0:00:51.980 seen what we see 0:00:56.640,0:00:59.040 asked the questions that we ask? 0:02:24.740,0:02:26.080 What we see around us 0:02:26.200,0:02:27.720 is staggering complexity 0:02:34.340,0:02:36.280 How is it possible? 0:02:41.540,0:02:43.740 Living organisms are created by chemistry 0:02:45.380,0:02:47.600 We are huge packages of chemicals 0:02:51.240,0:02:52.940 And what are the ideal conditions for chemistry? 0:02:54.300,0:02:56.740 Well, first, you need energy. 0:03:01.580,0:03:03.000 But not too much. 0:03:03.600,0:03:05.540 What you want is just the right amount 0:03:05.700,0:03:08.120 and planets it turns out are just right 0:03:08.120,0:03:10.360 because they are close to stars, but not too close 0:03:13.680,0:03:16.760 You also need a great diversity of chemical elements. 0:03:21.120,0:03:23.960 And you need liquid, such as water. 0:03:28.380,0:03:29.160 Why? 0:03:29.540,0:03:33.320 Well, is gases, atoms move past each other so fast 0:03:33.320,0:03:34.940 that they can't hitch up. 0:03:36.320,0:03:39.780 In solids, atoms are stuck together 0:03:39.780,0:03:41.500 they can’t move. 0:03:41.500,0:03:42.560 In liquids, 0:03:44.300,0:03:47.280 they can cruise and cuddle 0:03:47.280,0:03:49.980 and link up to form molecules. 0:03:56.400,0:03:59.240 liquid water is just so good 0:03:59.360,0:04:00.780 for getting evolution going 0:04:00.780,0:04:02.640 molecules can dissolve in the water, 0:04:02.640,0:04:04.500 form more complex chains 0:04:06.220,0:04:08.940 Now, where do you find such Goldilocks conditions? 0:04:09.200,0:04:11.880 Well, planets are great 0:04:12.140,0:04:14.920 and our early Earth was almost perfect 0:04:25.400,0:04:27.380 It was just the right distance from its star 0:04:27.380,0:04:30.340 to contain huge oceans of liquid water. 0:04:33.440,0:04:35.520 And deep beneath those oceans, 0:04:35.520,0:04:37.620 at cracks in the Earth's crust, 0:04:38.380,0:04:40.720 fantastic chemistry began to happen 0:04:41.080,0:04:43.860 and atoms combined in all sorts of exotic combinations. 0:05:59.280,0:06:00.520 here, on our planet, 0:06:01.200,0:06:02.860 microbes have adapted 0:06:02.860,0:06:06.080 to survive the most hostile conditions. 0:06:08.040,0:06:09.600 Arid deserts, 0:06:09.600,0:06:11.160 the frozen Himalayas 0:06:12.880,0:06:16.480 in trenches under thousands of tons of pressure 0:06:16.760,0:06:18.420 in the ocean deeps. 0:06:21.500,0:06:24.580 In the vacuum of a space simulator 0:06:24.580,0:06:27.820 life forms have been flourishing for years 0:06:29.160,0:06:31.380 without oxygen. 0:07:10.020,0:07:11.740 Very very quickly, 0:07:12.560,0:07:14.540 as soon as the Earth cooled off, 0:07:14.540,0:07:17.980 after its formation, we know that life began here. 0:07:22.820,0:07:25.440 Because it happened quickly here on Earth 0:07:25.440,0:07:27.060 we think it's going to happen quickly 0:07:27.080,0:07:28.920 on other planets as well. 0:09:17.940,0:09:21.980 We know that the galaxy is awash in water, 0:09:26.540,0:09:29.240 it’s awash in organic molecules, 0:09:29.240,0:09:31.180 and complex chemistry. 0:09:34.080,0:09:35.420 All of the things that we know 0:09:35.420,0:09:38.140 were necessary for life to begin on this planet 0:09:38.240,0:09:40.900 exist in abundance throughout the galaxy. 0:09:47.620,0:09:50.560 Did something similar to what happened on our own planet 0:09:50.560,0:09:53.620 happen on those other planets? 0:12:05.420,0:12:09.320 There are more habitable Earth-mass planets 0:12:09.320,0:12:11.660 in the observable volume of the universe 0:12:11.960,0:12:14.140 than there are grains of sand 0:12:14.140,0:12:16.480 on all the beaches on Earth. 0:15:50.840,0:15:54.300 The discovery of just one bacteria on Mars, 0:15:54.660,0:15:57.220 or any other body of the solar system, 0:15:57.720,0:16:01.480 would indicate that the whole chain of evolutions 0:16:01.800,0:16:04.640 cosmic, chemical, and biological 0:16:05.440,0:16:07.740 is at work everywhere. 0:16:08.200,0:16:09.760 In that case, 0:16:10.140,0:16:13.260 the creation of life anywhere in the universe 0:16:13.840,0:16:17.300 would be more the rule than the exception. 0:16:36.600,0:16:39.400 Within all of our lifetimes we're going to understand 0:16:39.480,0:16:42.000 that there is life on other bodies in the solar system. 0:16:49.500,0:16:51.900 We're going to understand the implications of that 0:16:51.900,0:16:53.520 for evolution of life here on Earth. 0:16:56.200,0:16:58.880 We're going to find planets around other stars 0:16:58.880,0:17:02.020 that we can say we see potential signs of habitability 0:17:02.020,0:17:04.680 in their atmospheres. 0:17:05.560,0:17:08.940 That's all going to happen in the next 10 to 20 years 0:17:10.000,0:17:11.680 How exciting is that? 0:17:13.960,0:17:15.400 We're on the verge of things 0:17:15.400,0:17:17.540 that people have wondered about for millennia: 0:17:17.540,0:17:19.100 "Are we alone?" 0:17:21.420,0:17:24.760 And here we are on the verge of finding that out. 0:17:48.100,0:17:51.220 The Universe is nearly 14 billion years old, 0:17:52.080,0:17:55.520 and our Galaxy is something like 12 billion years old. 0:17:56.200,0:17:58.900 So there could be life out there 0:17:58.900,0:18:01.100 that could be dramatically more advanced 0:18:01.100,0:18:04.500 than the life that we have here on this planet. 0:19:59.920,0:20:02.160 The only elements that were created in the Big Bang 0:20:02.460,0:20:05.620 where hydrogen, helium and a little bit of lithium. 0:20:07.780,0:20:10.140 All the stuff that makes your life livable - 0:20:10.220,0:20:13.160 those elements weren't created in the Big Bang. 0:20:15.540,0:20:17.100 The only place they're created 0:20:17.160,0:20:19.080 is in the fiery core of a star 0:20:19.080,0:20:21.460 and the only way for them to get into your body 0:20:22.120,0:20:24.680 is if those stars were kind enough to explode.