1 00:00:03,909 --> 00:00:05,909 Until now astronomers 2 00:00:05,920 --> 00:00:11,520 have found about four thousand confirmed planets outside our Solar System. 3 00:00:12,000 --> 00:00:14,190 Of these, Earth-like exoplanets 4 00:00:14,890 --> 00:00:16,890 often make headlines, 5 00:00:17,890 --> 00:00:23,130 such as Proxima B the closest rocky planet to our Solar System. 6 00:00:23,890 --> 00:00:25,890 This Earth-like exoplanet 7 00:00:26,140 --> 00:00:31,709 was found with the HARPS instrument on ESO's 3.6-metre telescope 8 00:00:32,000 --> 00:00:34,349 at La Silla Observatory. 9 00:00:35,300 --> 00:00:42,119 But ESO telescopes have helped find plenty of other exciting worlds some so exotic 10 00:00:42,640 --> 00:00:45,400 you would not dare to compare them with Earth. 11 00:00:46,120 --> 00:00:48,989 Meet the Stranger Exoplanets. 12 00:01:03,800 --> 00:01:06,249 Let's start with WASP-19b 13 00:01:06,560 --> 00:01:11,860 or as we like to call it, the inferno world with titanium skies. 14 00:01:13,280 --> 00:01:20,380 This hot Jupiter-sized planet has an atmosphere with a rather strange chemical composition. 15 00:01:20,960 --> 00:01:26,800 It was the first exoplanet where astronomers detected titanium oxide 16 00:01:27,000 --> 00:01:31,839 thanks to ESO's Very Large Telescope and its FORS2 instrument. 17 00:01:33,200 --> 00:01:38,740 This element acts as a heat absorber in the atmosphere of an inferno world. 18 00:01:39,440 --> 00:01:46,500 It can prevent heat from entering or escaping through the atmosphere leading to a thermal inversion. 19 00:01:46,850 --> 00:01:54,900 So on WASP-19b, the temperature could be higher in the upper atmosphere and lower further down, 20 00:01:55,430 --> 00:01:59,100 unlike what we see on our Solar System planets. 21 00:02:00,619 --> 00:02:06,519 We move on from this upside-down world to present you the Lonely Planet. 22 00:02:07,550 --> 00:02:09,200 A few years ago 23 00:02:09,200 --> 00:02:17,140 ESO telescopes and their instruments helped identify an object that could be a planet without any ties to a star. 24 00:02:17,960 --> 00:02:23,799 A free-floating world that rather than move around a star roams rogue through space. 25 00:02:25,280 --> 00:02:30,880 It could be that these planets have formed like other worlds around a parent star 26 00:02:31,430 --> 00:02:34,750 but then have been kicked out of their home system. 27 00:02:35,390 --> 00:02:39,970 So our Lonely Planet may well be an orphaned world. 28 00:02:42,710 --> 00:02:47,079 Our next strange exoplanet is not orphaned at all. 29 00:02:47,180 --> 00:02:52,090 In fact it hung on to its parent star through thick and thin. 30 00:02:53,360 --> 00:03:00,759 The Evaporating Exoplanet is the first giant planet ever found to be orbiting a white dwarf, 31 00:03:01,010 --> 00:03:03,600 the remnant of a Sun-like star. 32 00:03:04,670 --> 00:03:06,670 Astronomers think that this exoplanet 33 00:03:07,130 --> 00:03:14,109 survived the transition of its parent solar-type star to a red giant and then to a white dwarf. 34 00:03:14,780 --> 00:03:17,650 But that's not all that is strange about this planet. 35 00:03:18,700 --> 00:03:21,900 Observations with ESO's X-shooter on the VLT 36 00:03:22,200 --> 00:03:26,500 have hinted that this giant exoplanet is evaporating. 37 00:03:27,000 --> 00:03:32,890 It orbits the hot white dwarf at close range and the extreme ultraviolet 38 00:03:33,320 --> 00:03:37,500 radiation from the star strips away part of the planet's atmosphere 39 00:03:38,210 --> 00:03:41,000 forming a disc around the white dwarf. 40 00:03:41,870 --> 00:03:45,430 Our final alien world is even stranger 41 00:03:46,610 --> 00:03:48,500 WASP-76b 42 00:03:48,600 --> 00:03:52,540 an ultra hot giant exoplanet with a twist 43 00:03:53,960 --> 00:03:57,609 This planet orbits very close to its parent star 44 00:03:58,520 --> 00:04:03,999 receiving thousands of times more radiation from it than the Earth does from the Sun. 45 00:04:04,760 --> 00:04:07,400 It is also tidally locked, 46 00:04:07,670 --> 00:04:14,500 meaning it has a day side that always faces the star and a much cooler night side. 47 00:04:15,350 --> 00:04:19,000 The temperature difference on the planet is extreme. 48 00:04:19,300 --> 00:04:23,700 On the day side it is above 2400 degrees Celsius 49 00:04:23,800 --> 00:04:27,729 and everything including metals is vaporised. 50 00:04:28,550 --> 00:04:30,820 This is where things get really weird. 51 00:04:31,550 --> 00:04:35,020 Using the ESPRESSO instrument on the VLT, 52 00:04:35,300 --> 00:04:41,890 astronomers found that iron vapor from the ultra hot day side is carried to the cooler night side. 53 00:04:42,560 --> 00:04:47,380 There it condenses into iron droplets. In other words, 54 00:04:47,630 --> 00:04:52,500 this extreme exoplanet has a day side where metals evaporate 55 00:04:52,700 --> 00:04:56,200 and a night side where it rains iron. 56 00:04:57,970 --> 00:05:02,600 Will we find even stranger worlds? Well nobody knows. 57 00:05:02,920 --> 00:05:05,999 But astronomers keep on hunting for exoplanets. 58 00:05:07,420 --> 00:05:12,020 Stay tuned for future discoveries with ESO telescopes. 59 00:05:20,480 --> 00:05:30,280 Transcribed by ESO; Translated by —