1 00:00:02,090 --> 00:00:03,680 Over the last two decades, 2 00:00:03,680 --> 00:00:06,930 scientists have found thousands of planets elsewhere in the universe. 3 00:00:06,930 --> 00:00:08,760 These are called exoplanets. 4 00:00:08,760 --> 00:00:10,580 As we get better and better at finding them, 5 00:00:10,580 --> 00:00:13,940 we need ways to narrow down the ones most likely to support life. 6 00:00:13,940 --> 00:00:18,530 Two NASA rocket teams are working to do just that from Australia. 7 00:00:18,530 --> 00:00:23,140 Their mission? Study a special pair of stars best seen in the Southern Hemisphere – 8 00:00:23,140 --> 00:00:27,310 and propel humanity’s search for habitable worlds into the future. 9 00:00:27,310 --> 00:00:30,730 I’m Miles Hatfield and I’m following these rocket teams to Australia 10 00:00:30,730 --> 00:00:32,910 to show you what it takes to launch a rocket 11 00:00:32,910 --> 00:00:35,700 and make groundbreaking scientific measurements. 12 00:00:35,700 --> 00:00:45,240 Hang on tight – we’re going on an adventure High Above Down Under! 13 00:00:45,240 --> 00:00:50,260 Earth is packed with life! 14 00:00:50,260 --> 00:00:53,230 But some environments are more habitable than others. 15 00:00:53,230 --> 00:00:57,790 So what makes an environment – or a planet – a good place for life to thrive? 16 00:00:57,790 --> 00:00:59,990 Well, one thing is… 17 00:00:59,990 --> 00:01:02,300 Water! And in fact, 18 00:01:02,300 --> 00:01:06,120 that's what the search for life elsewhere in the universe has focused on so far, 19 00:01:06,120 --> 00:01:06,120 trying to find places where water can exist in liquid form. 20 00:01:06,120 --> 00:01:09,520 finding planets where water can exist in liquid form. 21 00:01:09,520 --> 00:01:13,600 There’s a region around every star that scientists call the goldilocks zone. 22 00:01:13,600 --> 00:01:17,560 A planet in this zone has the right temperature for water to remain liquid. 23 00:01:17,560 --> 00:01:20,340 Too close, and the water will evaporate away. 24 00:01:20,340 --> 00:01:22,290 Too far, and it will freeze. 25 00:01:22,290 --> 00:01:24,950 The distance has to be just right. 26 00:01:24,950 --> 00:01:28,790 This zone has been the basis for the search for habitable worlds. 27 00:01:28,790 --> 00:01:34,180 But just because a planet is inside the goldilocks zone, doesn’t mean it can sustain life. 28 00:01:34,180 --> 00:01:36,930 Take for example the closest known exoplanet to Earth 29 00:01:36,930 --> 00:01:39,170 at just 4.2 light-years away.  30 00:01:39,170 --> 00:01:41,370 It’s located in the goldilocks zone, 31 00:01:41,370 --> 00:01:43,950 but scientists think the star’s frequent eruptions 32 00:01:43,950 --> 00:01:46,980 might have blown away any atmosphere the planet might’ve had. 33 00:01:46,980 --> 00:01:50,550 In other words, the goldilocks zone is just a first guess. 34 00:01:50,550 --> 00:01:53,240 To truly tell whether an exoplanet is habitable, 35 00:01:53,240 --> 00:01:55,710 we need to look at the star it’s orbiting.  36 00:01:55,710 --> 00:02:00,700 Unfortunately we can’t just observe a planet and understand it at face value. 37 00:02:00,700 --> 00:02:05,550 We have to understand it in the context of what its parent star is giving it. 38 00:02:05,550 --> 00:02:11,150 So scientists have been collecting data from different types of stars to learn how they affect their planets. 39 00:02:11,150 --> 00:02:13,940 We would like to be able to create a menu of 40 00:02:13,940 --> 00:02:19,210 star-planet possibilities that our future missions can draw from 41 00:02:19,210 --> 00:02:25,850 and prioritize the most promising places to find habitable environments. 42 00:02:25,850 --> 00:02:27,770 The next item to be added to the menu? 43 00:02:27,770 --> 00:02:29,320 Yellow stars. 44 00:02:29,320 --> 00:02:33,470 We’re looking for something around five billion years old, an average size… 45 00:02:33,470 --> 00:02:36,190 Wait a second, don’t we have one right here? 46 00:02:36,190 --> 00:02:37,900 So why not use the Sun? 47 00:02:37,900 --> 00:02:45,750 We thought that our Sun is the prototype for kind of five-billion-year-old average yellow stars. 48 00:02:45,750 --> 00:02:47,740 What we've learned recently is that 49 00:02:47,740 --> 00:02:52,860 our Sun is actually quite inactive for a five-billion-year-old yellow star. 50 00:02:52,860 --> 00:02:55,220 Typical earthling behavior, really – 51 00:02:55,220 --> 00:02:58,020 thinking we’re the example for the entire universe.  52 00:02:58,020 --> 00:03:01,600 But it turns out yellow stars are found throughout our galaxy, 53 00:03:01,600 --> 00:03:05,900 and they tend to erupt with life-altering activity more often than our Sun does.  54 00:03:05,900 --> 00:03:09,210 So, If we want to understand if they can still support life, 55 00:03:09,210 --> 00:03:11,850 we’ll need more data than our Sun can give us. 56 00:03:11,850 --> 00:03:15,610 That’s why two rocket teams are looking to Alpha Centauri A and B. 57 00:03:15,610 --> 00:03:20,720 The reason why we're targeting Alpha Centauri is that it's our nearest solar twin. 58 00:03:20,720 --> 00:03:23,760 So in many, many ways, it's just like the Sun. 59 00:03:23,760 --> 00:03:26,740 It has almost the same mass, it's a very similar age. 60 00:03:26,740 --> 00:03:28,700 And it's nearby, which is always great. 61 00:03:28,700 --> 00:03:33,700 And with the help of NASA sounding rockets, they’ll capture light from those stars that doesn’t make it to the ground. 62 00:03:33,700 --> 00:03:39,140 This range of highly energetic ultraviolet light has never been measured before for these stars. 63 00:03:39,140 --> 00:03:42,430 Even small differences in this UV light from a star 64 00:03:42,430 --> 00:03:46,370 can determine whether a nearby planet can support life, or not. 65 00:03:46,370 --> 00:03:50,530 But the Alpha Centauri system isn't visible from most places in the U.S. 66 00:03:50,530 --> 00:03:54,260 It’s best studied from the Southern Hemisphere. 67 00:03:54,260 --> 00:03:56,070 That’s why we’re here in northern Australia 68 00:03:56,070 --> 00:03:58,260 in the traditional homeland of the Yolngu people. 69 00:03:58,260 --> 00:04:01,940 They’ve been observing the stars here for tens of thousands of years. 70 00:04:01,940 --> 00:04:05,470 I’m here with two rocket science teams, SISTINE and DEUCE, 71 00:04:05,470 --> 00:04:10,700 and a crew of about fifty NASA engineers, rocket specialists, and support staff.  72 00:04:10,700 --> 00:04:14,580 In partnership with Equatorial Launch Australia and the Gumatj Corporation, 73 00:04:14,580 --> 00:04:17,530 they’ve created an entire rocket range from scratch 74 00:04:17,530 --> 00:04:20,140 to help the scientists achieve their goals. 75 00:04:20,140 --> 00:04:23,560 In this series, you’re going to meet these teams and follow their quest, 76 00:04:23,560 --> 00:04:26,550 high above the Australian outback to see what it takes 77 00:04:26,550 --> 00:04:29,940 to make these first-ever measurements from our closest stellar neighbors. 78 00:04:29,940 --> 00:04:33,810 We’re going behind the scenes to learn more about the science of habitability 79 00:04:33,810 --> 00:04:35,650 and what goes into launching a rocket – 80 00:04:35,650 --> 00:04:38,760 dodging venomous snakes and crocodiles along the way. 81 00:04:38,760 --> 00:04:42,830 But first, we’ll take a look at how this brand new rocket range came to life 82 00:04:42,830 --> 00:04:47,460 with the help of the Yolngu people who have been observing these stars for millenia. 83 00:04:47,460 --> 00:04:48,040 84 00:04:48,040 --> 00:04:56,128 Heliophysics Big Year.