WEBVTT FILE 1 00:00:00.030 --> 00:00:04.010 [slate] 2 00:00:04.030 --> 00:00:08.020 [slate] 3 00:00:08.040 --> 00:00:12.080 4 00:00:12.100 --> 00:00:16.080 So exoplanets are planets 5 00:00:16.100 --> 00:00:20.090 outside of our solar system, they're orbiting other stars 6 00:00:20.110 --> 00:00:24.290 and that makes them very far away. So it's very difficult 7 00:00:24.310 --> 00:00:28.290 to observe details about exoplanets. We have to use special 8 00:00:28.310 --> 00:00:32.300 techniques to do that. The way we have used the Hubble Space 9 00:00:32.320 --> 00:00:36.320 Telescope to understand atmospheres of exoplanets is 10 00:00:36.340 --> 00:00:40.350 to look at those planets as they orbit around their parent star 11 00:00:40.370 --> 00:00:44.370 and when they sort of transit in front of that parent star, some of that starlight comes 12 00:00:44.390 --> 00:00:48.550 through the atmosphere surrounding the planet. And the atmosphere 13 00:00:48.570 --> 00:00:52.580 may absorb some of that light. And we can tell from the spectroscopic 14 00:00:52.600 --> 00:00:56.620 patterns of that light absorption what's in the atmosphere. 15 00:00:56.640 --> 00:01:00.640 In this case scientists have used the Hubble in this way to look at the spectroscopic 16 00:01:00.660 --> 00:01:04.660 signature of a planet transiting in front of its parent 17 00:01:04.680 --> 00:01:08.680 star to detect the signature of water vapor 18 00:01:08.700 --> 00:01:12.690 in the atmosphere of that exoplanet. And this is exciting news because it's not 19 00:01:12.710 --> 00:01:16.690 the first time we've seen water vapor in an exoplanet. There's some very 20 00:01:16.710 --> 00:01:20.870 large planets, big Jupiter-sized things that we've seen water vapor in. 21 00:01:20.890 --> 00:01:24.890 But this time, this planet is what we call a super-Earth. It's about eight times 22 00:01:24.910 --> 00:01:28.910 the mass of the Earth, which sounds big, but that's still a kind 23 00:01:28.930 --> 00:01:32.960 of planet that might be somewhat similar to Earth. And it also 24 00:01:32.980 --> 00:01:36.990 distance from its star where we might have moderate temperatures that would allow 25 00:01:37.010 --> 00:01:41.170 for liquid water and potentially habitability of that planet. 26 00:01:41.190 --> 00:01:45.190 So it's the next step in our investigations of exoplanets 27 00:01:45.210 --> 00:01:49.210 to see if any of them are like the planets in our own solar system. 28 00:01:49.230 --> 00:01:53.220 [slate] 29 00:01:53.240 --> 00:01:57.240 [slate] 30 00:01:57.260 --> 00:02:01.290 We don't know whether or not there could be life on 31 00:02:01.310 --> 00:02:05.290 this exoplanet. This is a next step in kind of studying what 32 00:02:05.310 --> 00:02:09.430 exoplanets are like. We're trying to understand if any of them could be 33 00:02:09.450 --> 00:02:13.460 very similar to Earth and could be habitable for life. 34 00:02:13.480 --> 00:02:17.620 One piece of that equation is to find planets like this one 35 00:02:17.640 --> 00:02:21.820 where the temperature might be moderate enough to allow water 36 00:02:21.840 --> 00:02:25.830 to be in liquid form - not so cold that it's frozen as ice 37 00:02:25.850 --> 00:02:29.830 or so hot that it boils away. This planet seems to be at that 38 00:02:29.850 --> 00:02:33.870 Goldilocks distance from its parent star to have potentially have 39 00:02:33.890 --> 00:02:37.890 liquid water and now we've seen water vapor in its atmosphere. But that's not 40 00:02:37.910 --> 00:02:42.090 the only characteristic of a planet that might be habitable. 41 00:02:42.110 --> 00:02:46.100 We also are concerned that the star that this planet is 42 00:02:46.120 --> 00:02:50.120 orbiting is probably very active. It's what we call a dwarf star. 43 00:02:50.140 --> 00:02:54.160 It may have some flaring. The planet is closer to its star 44 00:02:54.180 --> 00:02:58.190 than Earth is to our bigger sun. And it means that there might be heavy 45 00:02:58.210 --> 00:03:02.200 radiation coming on this planet which might it difficult for advanced life 46 00:03:02.220 --> 00:03:06.240 to thrive. We just don't know. But we've made this next step 47 00:03:06.260 --> 00:03:10.240 now of finding a super Earth with water vapor in the atmosphere and that's 48 00:03:10.260 --> 00:03:14.260 an exciting step to make. 49 00:03:14.280 --> 00:03:18.280 [slate] 50 00:03:18.300 --> 00:03:22.470 Well thanks to telescopes 51 00:03:22.490 --> 00:03:26.660 both on the ground and telescopes in space such as 52 00:03:26.680 --> 00:03:30.660 NASA's Kepler Space Telescope we understand that planets 53 00:03:30.680 --> 00:03:34.680 are quiet common in our galaxy. In fact many, 54 00:03:34.700 --> 00:03:38.700 if not most stars have at least one planet. Now those planets may 55 00:03:38.720 --> 00:03:42.710 not be similar to planet Earth, but planets themselves seem to be common. 56 00:03:42.730 --> 00:03:46.750 And so it's likely that there are 57 00:03:46.770 --> 00:03:50.770 millions and possibly billions of Earth 58 00:03:50.790 --> 00:03:54.810 or super-Earth sized exoplanets in the galaxy or 59 00:03:54.830 --> 00:03:58.860 orbiting other stars but most of them are very far away and very difficult 60 00:03:58.880 --> 00:04:02.890 for us to learn any great details about those exoplanets. 61 00:04:02.910 --> 00:04:06.910 We're better off looking at the near-by stars to find 62 00:04:06.930 --> 00:04:11.090 details, and we're doing that with some other NASA facilities as well 63 00:04:11.110 --> 00:04:15.130 like the TESS mission which is looking at planets round very bright stars in our 64 00:04:15.150 --> 00:04:19.140 neighborhood around the sun. And this information all works together 65 00:04:19.160 --> 00:04:23.330 to tell us some of the details of some of these exoplanets. 66 00:04:23.350 --> 00:04:27.330 But we believe exoplanets are very common and even Earth-mass, 67 00:04:27.350 --> 00:04:31.330 Earth-sized planets are probably fairly common in our galaxy. 68 00:04:31.350 --> 00:04:35.330 [slate] 69 00:04:35.350 --> 00:04:39.340 [slate] 70 00:04:39.360 --> 00:04:43.380 This particular planet is 71 00:04:43.400 --> 00:04:47.410 110 light years away. That means it's taken over 72 00:04:47.430 --> 00:04:51.420 100 years for the light from that system just to even get to our Hubble 73 00:04:51.440 --> 00:04:55.440 Space Telescope. For us to travel there would take 74 00:04:55.460 --> 00:04:59.510 many lifetimes. We don't have the technology yet 75 00:04:59.530 --> 00:05:03.620 to actually send a probe or any kind of mission to this 76 00:05:03.640 --> 00:05:07.640 system. So the way we are studying is by 77 00:05:07.660 --> 00:05:11.640 receiving the light from the star as it kind of comes through 78 00:05:11.660 --> 00:05:15.640 the atmosphere around the exoplanet as the planet orbits in front of the star 79 00:05:15.660 --> 00:05:19.670 And we can see what's in that atmosphere based on what the atmosphere absorbs from 80 00:05:19.690 --> 00:05:23.700 that starlight. That is the way we can explore this system with our current technology. 81 00:05:23.720 --> 00:05:27.700 [slate] 82 00:05:27.720 --> 00:05:31.750 [slate] 83 00:05:31.770 --> 00:05:35.750 Well we've used the Hubble Space Telescope 84 00:05:35.770 --> 00:05:39.810 for all of its mission basically to study planets 85 00:05:39.830 --> 00:05:43.880 in our own solar system. We have beautiful images of Jupiter 86 00:05:43.900 --> 00:05:47.910 and Saturn and we've also been studying their atmospheres. 87 00:05:47.930 --> 00:05:51.930 And the characteristics of their moons. But we're now using 88 00:05:51.950 --> 00:05:55.940 Hubble also to look at other star systems 89 00:05:55.960 --> 00:06:00.000 and their planets. When Hubble was launched back in 1990 we weren't even sure that 90 00:06:00.020 --> 00:06:04.060 there were abundance of planets around other stars. Hubble was not designed 91 00:06:04.080 --> 00:06:08.090 to do this kind of work. And yet now scientists are using Hubble to 92 00:06:08.110 --> 00:06:12.110 study the very compositions of atmospheres of planets orbiting 93 00:06:12.130 --> 00:06:16.130 other stars. We'd like to know how other planetary systems 94 00:06:16.150 --> 00:06:20.150 compare to our own solar system. And that is something Hubble is terrific at. 95 00:06:20.170 --> 00:06:24.170 [slate] 96 00:06:24.190 --> 00:06:28.190 [slate] The Hubble Space Telescope 97 00:06:28.210 --> 00:06:32.190 is turning 30 years old in 2020 98 00:06:32.210 --> 00:06:36.210 and it is in fantastic shape. The team 99 00:06:36.230 --> 00:06:40.210 of engineers and technical experts that oversee Hubble 100 00:06:40.230 --> 00:06:44.280 have kept it operating in tip top shape and we're grateful to astronauts who 101 00:06:44.300 --> 00:06:48.290 have returned to the Hubble several times over its mission to keep it 102 00:06:48.310 --> 00:06:52.290 refreshed with good instruments and supporting capabilities 103 00:06:52.310 --> 00:06:56.300 So right now we are getting the strongest science from the Hubble Space Telescope 104 00:06:56.320 --> 00:07:00.320 than we ever have and we expect that to continue for quite 105 00:07:00.340 --> 00:07:04.360 a few more years to come. In fact we're looking forward to an overlap of 106 00:07:04.380 --> 00:07:08.380 some years between the Hubble Space Telescope and the new James Webb 107 00:07:08.400 --> 00:07:12.410 Space Telescope that will launch in 2021. These telescopes 108 00:07:12.430 --> 00:07:16.430 will be complementary in terms of the information we get from them 109 00:07:16.450 --> 00:07:20.470 covering a spectrum of light all the way from what Hubble can see in the ultraviolet 110 00:07:20.490 --> 00:07:24.530 and visible parts of the light spectrum to the infrared 111 00:07:24.550 --> 00:07:28.590 part of the spectrum that Hubble can see and also the James Webb 112 00:07:28.610 --> 00:07:32.620 much deeper into the infrared part of the light spectrum. This teaches us 113 00:07:32.640 --> 00:07:36.620 a lot about exoplanets, about the stars 114 00:07:36.640 --> 00:07:40.650 that they orbit. About how they form and even about 115 00:07:40.670 --> 00:07:44.661 very distant star systems as well.