WEBVTT FILE 1 00:00:00.000 --> 00:00:04.000 [Music throughout] Astronomy is largely the study of light from distant places. 2 00:00:04.000 --> 00:00:08.000 Each kind of light carries different information that adds 3 00:00:08.000 --> 00:00:12.000 to our picture of the universe. 4 00:00:12.000 --> 00:00:16.000 The upcoming Nancy Grace Roman Space Telescope will detect a key 5 00:00:16.000 --> 00:00:20.000 range of light for studying the universe: visible into 6 00:00:20.000 --> 00:00:24.000 near-infrared. Infrared, which starts at a 7 00:00:24.000 --> 00:00:28.000 wavelength of about 0.75 microns, will allow the 8 00:00:28.000 --> 00:00:32.000 Roman Space Telescope to make many critical observations. Roman 9 00:00:32.000 --> 00:00:36.000 engineers now plan to add a new filter, extending its range 10 00:00:36.000 --> 00:00:40.000 from 2 to 2.3 microns. This seemingly small 11 00:00:40.000 --> 00:00:44.000 change will make a big difference. 12 00:00:44.000 --> 00:00:48.000 Our galaxy, the Milky Way, is filled with bands of dust and gas 13 00:00:48.000 --> 00:00:52.000 that block our view of the stars behind them. Part of 14 00:00:52.000 --> 00:00:56.000 what makes infrared light so useful to astronomers is its ability to 15 00:00:56.000 --> 00:01:00.000 travel through this gas and dust. Infrared light has a longer 16 00:01:00.000 --> 00:01:04.000 wavelength than visible light, which means it is less likely to be scattered 17 00:01:04.000 --> 00:01:08.000 and absorbed by small dust particles as it travels over long distances. 18 00:01:08.000 --> 00:01:12.000 Upgrading from 2 to 2.3 microns 19 00:01:12.000 --> 00:01:16.000 allows astronomers to see through two to three times as much dust. 20 00:01:16.000 --> 00:01:20.000 This opens up much more of our galaxy to study, including 21 00:01:20.000 --> 00:01:24.000 surveys of small, dim stars that glow mostly in infrared. 22 00:01:24.000 --> 00:01:28.000 Infrared is also good for studying the more 23 00:01:28.000 --> 00:01:32.000 distant parts of the universe. As the universe expands, 24 00:01:32.000 --> 00:01:36.000 it stretches the wavelengths of light along with it, a process called redshift. 25 00:01:36.000 --> 00:01:40.000 The farther away an object is, the more the light from it has 26 00:01:40.000 --> 00:01:44.000 stretched by the time it reaches us. Distant galaxies have all of 27 00:01:44.000 --> 00:01:48.000 their visible light shifted into infrared. 28 00:01:48.000 --> 00:01:52.000 Stretching over distance makes redshift one of the key tools for measuring the universe. 29 00:01:52.000 --> 00:01:56.000 Since astronomers can usually determine what wavelength 30 00:01:56.000 --> 00:02:00.000 they would see from up close, they can tell how far a galaxy is 31 00:02:00.000 --> 00:02:04.000 by how much the light has changed. 32 00:02:04.000 --> 00:02:08.000 Closer to home is the search for water within the solar system. Water ice 33 00:02:08.000 --> 00:02:12.000 absorbs specific wavelengths of infrared light, providing a “fingerprint" 34 00:02:12.000 --> 00:02:16.000 of its presence. As telescopes see farther into the infrared, 35 00:02:16.000 --> 00:02:20.000 they can see more of this fingerprint. If objects in the 36 00:02:20.000 --> 00:02:24.000 outer solar system, such as rocky fragments in the distant Kuiper Belt, contain 37 00:02:24.000 --> 00:02:28.000 water ice, light reflected off them will have gaps where the water 38 00:02:28.000 --> 00:02:32.000 has absorbed that wavelength. This allows astronomers to detect 39 00:02:32.000 --> 00:02:36.000 water at much greater distances. 40 00:02:36.000 --> 00:02:40.000 The Nancy Grace Roman Space Telescope will form an unprecedented 41 00:02:40.000 --> 00:02:44.000 partnership with Hubble and the James Webb Space Telescope. 42 00:02:44.000 --> 00:02:48.000 With its extremely large field of view, Roman is uniquely equipped 43 00:02:48.000 --> 00:02:52.000 for large surveys of the infrared sky, allowing astronomers 44 00:02:52.000 --> 00:02:56.000 to identify interesting targets for more detailed study 45 00:02:56.000 --> 00:03:00.000 using Hubble and Webb’s overlapping wavelength ranges and smaller fields of view. 46 00:03:00.000 --> 00:03:04.000 This collaboration will usher in a new era 47 00:03:04.000 --> 00:03:08.000 in infrared astronomy. 48 00:03:08.000 --> 00:03:12.000 49 00:03:12.000 --> 00:03:16.843 [NASA]