1 00:00:00,000 --> 00:00:03,980 [Music throughout] TESS, the Transiting 2 00:00:04,000 --> 00:00:07,980 Exoplanet Survey Satellite, is NASA’s newest planet hunter. 3 00:00:08,000 --> 00:00:11,980 The mission has operated for two years and has now mapped about 4 00:00:12,000 --> 00:00:15,980 75% of the sky. This enormous area of coverage 5 00:00:16,000 --> 00:00:19,980 gives scientists unprecedented opportunities to search for new worlds 6 00:00:20,000 --> 00:00:23,980 beyond our solar system as well as other cosmic phenomena. 7 00:00:24,000 --> 00:00:27,980 TESS completed its initial sky survey in July 2020. 8 00:00:28,000 --> 00:00:31,980 This giant mosaic is made from 26 sector images. 9 00:00:32,000 --> 00:00:35,980 Each sector is a 24-by-96-degree strip of sky, 10 00:00:36,000 --> 00:00:39,980 monitored by TESS’s four cameras for about a month. Here 11 00:00:40,000 --> 00:00:43,980 are some of the noteworthy discoveries from TESS’s second year. 12 00:00:44,000 --> 00:00:47,980 TESS discovered a trio of planets around GJ-357, a 13 00:00:48,000 --> 00:00:51,980 red dwarf star just 31 light-years away. The system’s farthest planet, 14 00:00:52,000 --> 00:00:55,980 with about six times Earth’s mass, is especially intriguing. 15 00:00:56,000 --> 00:00:59,980 It orbits in the outer part of the star’s habitable zone. If this planet has an 16 00:01:00,000 --> 00:01:03,980 atmosphere thick enough to keep its surface warm, liquid water could exist there. 17 00:01:04,000 --> 00:01:07,980 TESS found another planetary trio around the star 18 00:01:08,000 --> 00:01:11,980 L98-59. The innermost world is the littlest found by TESS, 19 00:01:12,000 --> 00:01:15,980 and is 20% smaller than Earth. Later, 20 00:01:16,000 --> 00:01:19,980 scientists announced TESS had observed a star being torn apart by a black hole. 21 00:01:20,000 --> 00:01:23,980 Catching one of these tidal disruption events showcases 22 00:01:24,000 --> 00:01:27,980 the mission’s ability to spot many kinds of short-lived phenomena, like 23 00:01:28,000 --> 00:01:31,980 stellar outbursts and supernovae, underscoring TESS’s importance 24 00:01:32,000 --> 00:01:35,980 for studies beyond exoplanets. In early 2020, 25 00:01:36,000 --> 00:01:39,980 scientists announced TESS’s first Earth-size planet orbiting in its star’s habitable 26 00:01:40,000 --> 00:01:43,980 zone. This world, called TOI 700 d, 27 00:01:44,000 --> 00:01:47,980 is a little larger than Earth and probably rocky. Based on 28 00:01:48,000 --> 00:01:51,980 TESS and Spitzer data, researchers were even able to model potential 29 00:01:52,000 --> 00:01:55,980 weather systems. Analysis of the planet’s atmosphere, if it has one, 30 00:01:56,000 --> 00:01:59,980 will have to await future space-based observatories like NASA's 31 00:02:00,000 --> 00:02:03,980 James Webb Space Telescope. Missons like TESS — and later Webb — 32 00:02:04,000 --> 00:02:07,980 help contribute to the field of astrobiology, the interdisciplinary 33 00:02:08,000 --> 00:02:11,980 research on the variables and conditions of distant worlds that could 34 00:02:12,000 --> 00:02:15,980 harbor life as we know it. TESS has found many systems different 35 00:02:16,000 --> 00:02:19,980 from our own. TOI 1338 has a Neptune-size planet 36 00:02:20,000 --> 00:02:23,980 orbiting a pair of stars. KELT-9 has a fast-spinning 37 00:02:24,000 --> 00:02:27,980 star with hot poles and a cooler equator. KELT-9 b 38 00:02:28,000 --> 00:02:31,980 orbits over the poles, resulting in star-induced seasons that only 39 00:02:32,000 --> 00:02:35,980 last a few hours. Now that its primary mission is 40 00:02:36,000 --> 00:02:39,980 complete, TESS will return to the southern sky for another yearlong survey. 41 00:02:40,000 --> 00:02:42,980 Many new planets, as well as more brief cataclysmic events, 42 00:02:43,000 --> 00:02:47,150 await astronomers as they scour the flood 43 00:02:47,170 --> 00:02:51,270 of TESS observations. 44 00:02:51,290 --> 00:02:55,410 Explore: solar system & beyond 45 00:02:55,430 --> 00:02:57,724 NASA