1 00:00:07,500 --> 00:00:12,000 Not long ago, actually watching something being ripped apart as it falls 2 00:00:12,000 --> 00:00:16,000 towards a giant black hole would be science fiction. 3 00:00:16,000 --> 00:00:22,000 But this is becoming reality for astronomers using ESO’s Very Large Telescope. 4 00:00:26,000 --> 00:00:28,000 This is the ESOcast! 5 00:00:28,000 --> 00:00:31,000 Cutting-edge science and life behind the scenes of ESO, 6 00:00:31,000 --> 00:00:34,000 the European Southern Observatory. 7 00:00:45,000 --> 00:00:48,000 Hello, and welcome to the ESOcast. 8 00:00:48,000 --> 00:00:52,500 In this episode we will see how science fiction has turned into science fact 9 00:00:52,500 --> 00:00:56,500 as astronomers observe the progressive destruction of a cloud of gas 10 00:00:56,500 --> 00:01:00,000 that’s being pulled in by a supermassive black hole. 11 00:01:02,000 --> 00:01:05,500 ESO telescopes have been used to track the motion of stars 12 00:01:05,500 --> 00:01:10,000 around the giant black hole at the centre of our galaxy for 20 years. 13 00:01:11,000 --> 00:01:15,000 This black hole’s mass is a hefty four million times that of the Sun, 14 00:01:15,000 --> 00:01:19,000 earning it the title of supermassive black hole. 15 00:01:20,000 --> 00:01:21,000 Although it is huge, 16 00:01:21,000 --> 00:01:26,000 this black hole is currently supplied with little material and is not shining brightly, 17 00:01:26,000 --> 00:01:29,000 but this is about to change. 18 00:01:32,000 --> 00:01:34,500 Using ESO’s Very Large Telescope, 19 00:01:34,500 --> 00:01:37,000 a team of astronomers has discovered a new object 20 00:01:37,000 --> 00:01:42,000 that is heading almost straight towards the black hole at vertiginous speed. 21 00:01:42,000 --> 00:01:46,000 The object is not a star, but a cloud of gas. 22 00:01:47,000 --> 00:01:50,000 The cloud consists mainly of hydrogen gas, 23 00:01:50,000 --> 00:01:53,500 gas which we see anyhow in the galactic centre all over the place. 24 00:01:53,500 --> 00:01:57,000 This particular cloud weighs more or less three times the mass of Earth. 25 00:01:57,000 --> 00:02:00,000 So it’s a rather small and tiny blob only, 26 00:02:00,000 --> 00:02:06,000 but it glows very brightly in the light of the stars which are surrounding the cloud. 27 00:02:08,000 --> 00:02:09,000 As the astronomers watched, 28 00:02:09,000 --> 00:02:14,000 the cloud has been picking up pace as it gets closer to the giant black hole. 29 00:02:14,000 --> 00:02:17,000 Its speed has doubled in the last seven years 30 00:02:17,000 --> 00:02:23,000 and it is now speeding towards the black hole at more than 8 million km/h. 31 00:02:24,000 --> 00:02:28,000 The astronomers have already seen the cloud’s outer layers becoming 32 00:02:28,000 --> 00:02:33,000 more and more disrupted over the last few years as it approaches the black hole. 33 00:02:33,000 --> 00:02:37,000 But the exciting part is yet to come. 34 00:02:38,000 --> 00:02:40,000 The Black hole, imagine it sitting here, 35 00:02:40,000 --> 00:02:42,000 has a tremendous gravitational force 36 00:02:42,000 --> 00:02:46,000 and the cloud, as it comes in, it will be elongated and stretched, 37 00:02:46,000 --> 00:02:48,000 it will become essentially like spaghetti. 38 00:02:48,000 --> 00:02:51,000 It will be elongated and falling into the black hole. 39 00:02:52,000 --> 00:02:55,500 The next few years will be really fantastic and exciting 40 00:02:55,500 --> 00:02:57,000 because we are probing the territory. 41 00:02:57,000 --> 00:02:59,000 Here this cloud comes and gets disrupted, 42 00:02:59,000 --> 00:03:05,000 but now it will begin to interact with the hot gas right around the black hole. 43 00:03:05,000 --> 00:03:06,000 We have never seen this before. 44 00:03:09,000 --> 00:03:11,000 No one knows what will happen next. 45 00:03:11,000 --> 00:03:13,000 The cloud will probably heat up 46 00:03:13,000 --> 00:03:17,000 and may start to emit powerful X-rays as it gets disrupted. 47 00:03:17,000 --> 00:03:22,000 In the end the material will eventually disappear by falling into the black hole. 48 00:03:22,000 --> 00:03:24,000 For the scientists, 49 00:03:24,000 --> 00:03:29,000 this event is truly a unique chance to probe the hot gas around the black hole. 50 00:03:39,000 --> 00:03:43,000 This process of how material gets into the black hole really is not clear to us 51 00:03:43,000 --> 00:03:44,000 we don’t understand it in any detail. 52 00:03:44,000 --> 00:03:48,000 And here in the galactic centre we have an opportunity so to speak 53 00:03:48,000 --> 00:03:50,500 to have a probe of this process. 54 00:03:50,500 --> 00:03:54,500 How material really gets added to the black hole, and what the physical processes are, 55 00:03:54,500 --> 00:03:57,500 how the interactions happen in this very central region. 56 00:03:57,500 --> 00:03:59,500 That’s a fantastic opportunity. 57 00:04:03,000 --> 00:04:07,500 This is indeed science fiction becoming science fact. 58 00:04:18,000 --> 00:04:21,000 ESOcast is produced by ESO, the European Southern Observatory. 59 00:04:21,500 --> 00:04:23,500 ESO, the European Southern Observatory, 60 00:04:23,500 --> 00:04:26,000 is the pre-eminent intergovernmental science and technology organisation in astronomy, 61 00:04:26,000 --> 00:04:29,000 designing, constructing and operating the world’s most advanced ground-based telescopes. 62 00:04:30,000 --> 00:04:35,000 Transcription by ESO; translation by — 63 00:04:47,000 --> 00:04:50,000 Now that you've caught up with ESO, 64 00:04:52,000 --> 00:04:55,000 head 'out of this world' with Hubble. 65 00:04:58,000 --> 00:05:01,000 The Hubblecast highlights the latest discoveries 66 00:05:01,000 --> 00:05:04,000 of the world´s most recognized and prized space observatory, 67 00:05:07,000 --> 00:05:10,000 The NASA/ESA Hubble Space Telescope.