WEBVTT FILE 1 00:00:00.000 --> 00:00:03.980 [slate] 2 00:00:04.000 --> 00:00:07.990 [slate] 3 00:00:08.010 --> 00:00:11.990 First of all, we see these beautiful 4 00:00:12.010 --> 00:00:15.990 clouds of gas and dust where stars form. And now we're 5 00:00:16.010 --> 00:00:19.990 starting to detect these objects that have been ejected out of other star 6 00:00:20.010 --> 00:00:24.170 systems. Have traveled through interstellar space and are now whizzing 7 00:00:24.190 --> 00:00:28.180 through our own solar system. From these objects we can understand 8 00:00:28.200 --> 00:00:32.180 how they formed as we look at their composition and nature 9 00:00:32.200 --> 00:00:36.190 and compare that to how our own solar system and objects here formed. 10 00:00:36.210 --> 00:00:40.190 And see how we're similar and different. [slate] 11 00:00:40.210 --> 00:00:44.190 [slate] 12 00:00:44.210 --> 00:00:48.370 With Hubble's very high resolution 13 00:00:48.390 --> 00:00:52.380 we can hone in on the nucleus, the center part of that comet's 14 00:00:52.400 --> 00:00:56.380 core and see how it separates or is different from the surrounding 15 00:00:56.400 --> 00:01:00.400 more nebulous, dusty, gassy coma around 16 00:01:00.420 --> 00:01:04.400 the nucleus. [slate] 17 00:01:04.420 --> 00:01:08.410 [slate] 18 00:01:08.430 --> 00:01:12.420 We know of a lot of comets in our solar system, 19 00:01:12.440 --> 00:01:16.420 famous ones like Comet Halley and a lot of comets that are not so famous. 20 00:01:16.440 --> 00:01:20.430 But they all originate in our own solar system. Usually from the outer 21 00:01:20.450 --> 00:01:24.430 reaches of the solar system, and come near to the sun occasionally. 22 00:01:24.450 --> 00:01:28.430 This new object discovered came from outside 23 00:01:28.450 --> 00:01:32.440 our solar system. From some other star system and has traveled across 24 00:01:32.460 --> 00:01:36.440 space and is whizzing through our solar system for one quick pass. 25 00:01:36.460 --> 00:01:40.450 So we want to study it very well while we can. 26 00:01:40.470 --> 00:01:44.460 [slate] 27 00:01:44.480 --> 00:01:48.470 We're really excited because this 28 00:01:48.490 --> 00:01:52.480 is only the second time we've seen an object whizzing through the 29 00:01:52.500 --> 00:01:56.530 solar system from interstellar space. Now recently 30 00:01:56.550 --> 00:02:00.550 we also observed an object called 'Oumuamua. This is more like 31 00:02:00.570 --> 00:02:04.550 an asteroid object whizzing through the solar system. And now 32 00:02:04.570 --> 00:02:08.560 the second object that we've detected looks more like a comet. 33 00:02:08.580 --> 00:02:12.740 It's got a nucleus but kind of a fuzzy cloud around it we call a coma 34 00:02:12.760 --> 00:02:16.750 that's got gas and dust. So by comparing 35 00:02:16.770 --> 00:02:20.760 these two objects we'll be able to understand more about 36 00:02:20.780 --> 00:02:24.770 interstellar objects, their origins, and what they're like. 37 00:02:24.790 --> 00:02:28.770 [slate] 38 00:02:28.790 --> 00:02:32.770 [slate] 39 00:02:32.790 --> 00:02:36.770 Interstellar space, is the space basically the space between 40 00:02:36.790 --> 00:02:40.780 stars. Stars are a long way from one another and interstellar 41 00:02:40.800 --> 00:02:44.790 space is all that region between those stars. 42 00:02:44.810 --> 00:02:48.790 [slate] 43 00:02:48.810 --> 00:02:52.790 An interstellar object 44 00:02:52.810 --> 00:02:56.790 would be something like a comet or an asteroid that's traveling between 45 00:02:56.810 --> 00:03:00.810 stars and star systems. 46 00:03:00.830 --> 00:03:05.000 [slate] 47 00:03:05.020 --> 00:03:09.180 Studying comets is very important because 48 00:03:09.200 --> 00:03:13.190 comets tell us something about how star systems formed. 49 00:03:13.210 --> 00:03:17.190 They're usually made of material that's very pristine and preserved from 50 00:03:17.210 --> 00:03:21.190 early parts of the formation of that star system. 51 00:03:21.210 --> 00:03:25.200 [slate] 52 00:03:25.220 --> 00:03:29.200 [slate] 53 00:03:29.220 --> 00:03:33.220 A comet is an object usually thought of as kind of an 54 00:03:33.240 --> 00:03:37.220 a conglomeration of dust and ice, kind of loosely 55 00:03:37.240 --> 00:03:41.220 held together. A little more loosely than what we might think of as an asteroid or 56 00:03:41.240 --> 00:03:43.403 a hard rock.