1 00:00:00,533 --> 00:00:04,237 So X-rays really show us that the universe 2 00:00:04,237 --> 00:00:07,340 is very energetic. 3 00:00:08,908 --> 00:00:11,011 We find X-rays in jets 4 00:00:11,378 --> 00:00:14,414 erupting from the centers of active galaxies. 5 00:00:15,682 --> 00:00:19,519 We use them to measure the spin of black holes 6 00:00:19,853 --> 00:00:22,622 or supernova explosions. 7 00:00:23,890 --> 00:00:25,959 It takes a powerful event 8 00:00:26,359 --> 00:00:29,462 to produce cosmic X-rays. 9 00:00:29,462 --> 00:00:31,598 Sometimes people also call it the hot universe 10 00:00:32,132 --> 00:00:34,034 because, you know, when you have this gas 11 00:00:34,034 --> 00:00:37,637 in galaxy clusters or also around galaxies that you can see only in X-rays. 12 00:00:38,004 --> 00:00:41,041 This gas is about 10 million to 100 million degrees, 13 00:00:41,041 --> 00:00:45,278 which is so hot that this gas does not radiate in the 14 00:00:45,278 --> 00:00:48,515 optical, does not radiate in the infrared, but only radiates in X-rays. 15 00:00:50,283 --> 00:00:53,053 To understand these hottest regions. 16 00:00:53,553 --> 00:00:56,056 We need the next-generation X-ray 17 00:00:56,122 --> 00:01:01,728 telescope. 18 00:01:01,728 --> 00:01:06,866 The Japan Aerospace Exploration Agency, or JAXA, is partnering with NASA 19 00:01:07,100 --> 00:01:11,071 and the European Space Agency to launch the next-generation 20 00:01:11,071 --> 00:01:14,841 X-ray Space Telescope. 21 00:01:16,976 --> 00:01:17,944 The telescope, 22 00:01:17,944 --> 00:01:21,748 called XRISM, launches from the Tanegashima Space Center 23 00:01:21,815 --> 00:01:24,851 at the southern end of Japan on an H-IIA 24 00:01:24,884 --> 00:01:27,120 rocket. 25 00:01:28,922 --> 00:01:31,024 The spacecraft weighs over 5,000 26 00:01:31,024 --> 00:01:34,861 pounds, stands over 30 feet tall and will orbit 27 00:01:34,861 --> 00:01:39,732 approximately 340 miles above Earth. 28 00:01:41,501 --> 00:01:44,204 We're familiar with the medical uses of X-rays. 29 00:01:44,938 --> 00:01:48,541 X-ray light is energetic enough to pass through our skin. 30 00:01:49,242 --> 00:01:52,445 Our calcium dense bones absorb that light, 31 00:01:52,879 --> 00:01:56,282 blocking it from reaching the detector and creating a shadow. 32 00:01:58,051 --> 00:01:59,752 Luckily for us, X-rays 33 00:01:59,752 --> 00:02:02,455 from space don't make it through our atmosphere. 34 00:02:02,956 --> 00:02:05,792 But what that does mean is that we have to send X-ray 35 00:02:05,825 --> 00:02:09,529 hunting missions into orbit to detect this high-energy 36 00:02:09,529 --> 00:02:11,531 light. 37 00:02:13,533 --> 00:02:16,236 XRISM also needs special kinds of mirrors, 38 00:02:16,803 --> 00:02:19,305 which are built at NASA's Goddard Space Flight Center. 39 00:02:20,940 --> 00:02:23,743 The type of the mirror is called nested mirror 40 00:02:24,511 --> 00:02:28,948 that looks like a cross-section of an onion. 41 00:02:34,921 --> 00:02:36,055 X-rays are 42 00:02:36,055 --> 00:02:39,192 so energetic, they fly right through typical mirrors 43 00:02:40,627 --> 00:02:41,528 For the visible light, 44 00:02:41,528 --> 00:02:45,899 we typically place them like this, so that light just bounces back. 45 00:02:46,366 --> 00:02:48,968 But for the X-rays, this doesn't work 46 00:02:49,302 --> 00:02:52,105 so that we put the mirror like this, 47 00:02:53,039 --> 00:02:57,944 so that X-rays just grazes the surface of the shell. 48 00:02:58,845 --> 00:03:02,081 When they strike mirrors at very shallow angles, 49 00:03:02,382 --> 00:03:06,152 X-rays, too, can bounce. 50 00:03:08,254 --> 00:03:10,456 And then so we made it like a conical shell, 51 00:03:10,490 --> 00:03:11,424 like this. 52 00:03:11,424 --> 00:03:15,428 Then X-ray can be directed. 53 00:03:20,133 --> 00:03:20,567 XRISM 54 00:03:20,567 --> 00:03:23,937 has two instruments, each with their own mirror assembly, 55 00:03:24,270 --> 00:03:28,341 one for imaging, called Xtend, the other for spectroscopy, 56 00:03:28,675 --> 00:03:31,344 called Resolve. 57 00:03:32,412 --> 00:03:35,682 JAXA built Xtend to provide XRISM with a wide 58 00:03:35,682 --> 00:03:42,255 field of view. It can observe an area about 60% larger 59 00:03:42,422 --> 00:03:46,926 than the average appearance size of the full moon. 60 00:03:48,361 --> 00:03:50,029 NASA's Resolve instrument 61 00:03:50,029 --> 00:03:53,533 is a spectrometer that splits X-ray light like a prism 62 00:03:54,200 --> 00:03:56,569 so scientists can detect specific 63 00:03:56,569 --> 00:03:58,972 elements present in the sources they're studying. 64 00:03:59,839 --> 00:04:02,642 It uses a small six-by-six 65 00:04:02,642 --> 00:04:06,779 pixel detector called a microcalorimeter, nestled 66 00:04:06,779 --> 00:04:11,851 in a refrigerator-sized container of liquid helium. 67 00:04:12,652 --> 00:04:15,321 Resolve will measure the small temperature changes 68 00:04:15,321 --> 00:04:18,224 caused when X-rays hit one of those pixels. 69 00:04:18,758 --> 00:04:22,028 To track such small temperature changes, Resolve’s 70 00:04:22,028 --> 00:04:25,465 detectors must be kept extremely cold. 71 00:04:26,299 --> 00:04:29,636 That liquid helium cryocooler will keep the instrument 72 00:04:29,636 --> 00:04:32,205 at 0.05 degrees. 73 00:04:34,774 --> 00:04:36,609 It's so cold 74 00:04:36,609 --> 00:04:39,145 it is a fraction of a degree above 75 00:04:39,145 --> 00:04:42,181 absolute zero. 76 00:04:42,181 --> 00:04:45,184 Heat is simply a product of moving atoms 77 00:04:45,685 --> 00:04:50,723 keeping Resolve’s detector that cold means that the atoms barely move. 78 00:04:51,691 --> 00:04:54,427 So there's very little thermal noise in the system. 79 00:04:55,962 --> 00:04:58,264 It's what keeps these accurate measurements 80 00:04:58,765 --> 00:05:06,439 possible. 81 00:05:06,873 --> 00:05:09,776 Each X-ray detected will help scientists pursue 82 00:05:10,043 --> 00:05:13,346 many questions about the hottest regions of the cosmos. 83 00:05:14,781 --> 00:05:16,115 What's happening 84 00:05:16,115 --> 00:05:19,085 in the extreme gravitational fields around black 85 00:05:19,085 --> 00:05:21,421 holes? 86 00:05:24,090 --> 00:05:26,025 Can we discover 87 00:05:26,025 --> 00:05:29,529 what is inside a neutron star? 88 00:05:31,564 --> 00:05:34,500 How did some of the universe's largest structures 89 00:05:34,701 --> 00:05:38,838 like galaxy clusters, evolve? 90 00:05:40,039 --> 00:05:41,040 Optical Telescope, 91 00:05:41,040 --> 00:05:43,109 you will just see galaxies everywhere. 92 00:05:43,576 --> 00:05:47,213 If you if you look at this same cluster of galaxies in X-rays, 93 00:05:47,213 --> 00:05:49,115 you will see actually a lot of gas. 94 00:05:49,115 --> 00:05:52,018 And this gas constitutes actually most of the matter 95 00:05:52,018 --> 00:05:55,121 the cluster of the galaxies, which is something it's important 96 00:05:55,555 --> 00:05:58,024 to to understand, because it means that most of the matter 97 00:05:58,725 --> 00:06:01,728 in the universe is not in the form of planets or stars, 98 00:06:01,728 --> 00:06:06,733 but it's really in the form of this all of this gas. So. 99 00:06:07,767 --> 00:06:12,271 But XRISM really has this capability of decomposing this X-ray light 100 00:06:12,271 --> 00:06:15,108 in a way that's much, much more accurate than what has 101 00:06:15,274 --> 00:06:22,348 ever been done before.