1 00:00:09,360 --> 00:00:14,500 Your home and the universe have at least one thing in common – they can be very dusty places. 2 00:00:14,840 --> 00:00:18,860 When you get back after a very long vacation, it may happen that the windows in your home 3 00:00:18,860 --> 00:00:21,480 are so full of dust that you can't see through them anymore. 4 00:00:22,020 --> 00:00:26,300 Surprisingly, astronomers have a similar problem when using optical telescopes – 5 00:00:26,300 --> 00:00:28,700 telescopes that can see the same light that we do. 6 00:00:29,040 --> 00:00:31,740 They are not able to see through the dustiest places in the universe, 7 00:00:32,040 --> 00:00:34,500 as they appear like dark walls blocking the view. 8 00:00:34,940 --> 00:00:39,340 And just as you may miss lots of interesting things happening outside because of the dusty glass, 9 00:00:39,340 --> 00:00:44,480 Some of the most important events in the universe occur within vast clouds of cold dust and gas. 10 00:00:44,480 --> 00:00:49,340 Stars and planets, for example, are born within those clouds, which are dark to most telescopes. 11 00:00:49,780 --> 00:00:52,520 Astronomers want to understand how these births happen, 12 00:00:52,520 --> 00:00:55,100 as both stars and their planets are essential for life. 13 00:00:55,100 --> 00:00:59,160 You need a planet to live on and a star to provide the energy that allows you to survive. 14 00:00:59,660 --> 00:01:00,920 So there are two options... 15 00:01:00,920 --> 00:01:05,280 Either find a way to clean the dust, or get some special goggles that can see through it. 16 00:01:05,280 --> 00:01:08,940 For you the first option would be easier, but astronomers have no choice. 17 00:01:08,940 --> 00:01:14,520 They can't clean the dust out of space – they need to build something special that can see through dust. 18 00:01:14,520 --> 00:01:19,220 With the help of engineers, they created radio telescopes, and Alma is one of them. 19 00:01:19,940 --> 00:01:24,740 These are telescopes that see a kind of light, called radio light, that is not blocked by dust. 20 00:01:25,240 --> 00:01:28,000 Moreover some things in the universe are so cold, 21 00:01:28,000 --> 00:01:30,380 that they don't produce enough energy to be seen in visible light. 22 00:01:30,840 --> 00:01:36,300 However they happen to emit radio light, because this kind of light is produced by less energetic processes. 23 00:01:36,800 --> 00:01:39,460 Therefore even though you can see our Sun, and other stars, 24 00:01:39,460 --> 00:01:42,200 through their childhood, teenage years, and adulthood, 25 00:01:42,200 --> 00:01:45,820 Only radio telescopes are able to see stars that are just being born, 26 00:01:45,820 --> 00:01:47,540 and aren't producing enough energy yet. 27 00:01:48,200 --> 00:01:53,820 Only radio telescopes, as well, can look at the planets forming in the dusty discs around those newborn stars. 28 00:01:54,180 --> 00:01:57,100 So why are there some stars that get to be so much larger than others? 29 00:01:57,540 --> 00:01:59,600 How do planets form around newborn stars? 30 00:02:00,040 --> 00:02:02,760 Why are some star systems so different from our own? 31 00:02:03,140 --> 00:02:05,980 Well these are questions ALMA will help unravel. 32 00:02:08,940 --> 00:02:12,740 Transcribed by ESO; Translated by —