1 00:00:00,000 --> 00:00:07,600 Hello everyone, I'm Brad Breckenridge, filling in for Steel McGonagall. 2 00:00:07,600 --> 00:00:08,920 And I'm Kara O'Brien. 3 00:00:08,920 --> 00:00:11,400 Welcome to Destination Tomorrow. 4 00:00:11,400 --> 00:00:16,020 This program will uncover how past, present, and future research is creating today's knowledge 5 00:00:16,020 --> 00:00:19,400 to answer the questions and solve the challenges of tomorrow. 6 00:00:19,400 --> 00:00:23,840 We begin with a look at a fascinating moon called Titan, which is orbiting around the 7 00:00:23,840 --> 00:00:25,440 planet Saturn. 8 00:00:25,440 --> 00:00:29,960 This moon has become the subject of much scientific speculation in recent years, since it was 9 00:00:29,960 --> 00:00:34,680 discovered to have an atmosphere roughly four times thicker than Earth's. 10 00:00:34,680 --> 00:00:39,360 About half the size of Earth, this small planet-like moon has an atmosphere that contains large 11 00:00:39,360 --> 00:00:41,640 amounts of nitrogen and carbon. 12 00:00:41,640 --> 00:00:45,960 This is important because these chemicals are considered by many scientists to be the 13 00:00:45,960 --> 00:00:48,720 building blocks for life as we know it. 14 00:00:48,720 --> 00:00:53,360 Little is known about Titan's surface because its thick atmosphere hides it from view. 15 00:00:53,360 --> 00:00:58,120 To help us learn more about Titan, NASA scientists have launched an intriguing mission to explore 16 00:00:58,120 --> 00:00:59,640 this distant moon. 17 00:00:59,720 --> 00:01:03,640 This mission, called Cassini-Huygens, was launched from Kennedy Space Center on October 18 00:01:03,640 --> 00:01:06,000 15, 1997. 19 00:01:06,000 --> 00:01:10,640 Once at Saturn, the Cassini-Huygens spacecraft will not only study Saturn's atmosphere and 20 00:01:10,640 --> 00:01:16,040 its other moons, but will also drop a small lander onto the surface of Titan. 21 00:01:16,040 --> 00:01:20,680 While Cassini-Huygens will dramatically boost our knowledge of Titan, it will likely lead 22 00:01:20,680 --> 00:01:24,440 to more questions about this interesting moon. 23 00:01:24,440 --> 00:01:29,240 Tonya St. Romain spoke with researcher Dr. Marianne Rudisill to find out more about the 24 00:01:29,240 --> 00:01:36,960 current mission and possible future missions to Titan. 25 00:01:36,960 --> 00:01:41,920 One of NASA's stated goals is to search for life and life-enabling conditions such as 26 00:01:41,920 --> 00:01:45,480 water and lifelike chemistry throughout the universe. 27 00:01:45,480 --> 00:01:49,720 In recent years, the task of searching for life has become much easier with the development 28 00:01:49,720 --> 00:01:54,980 of tools like the Hubble Space Telescope and advanced sensors aboard spacecraft. 29 00:01:54,980 --> 00:01:59,220 With these technology advancements, NASA scientists are now able to better identify 30 00:01:59,220 --> 00:02:02,420 so-called hotspot locations in the universe. 31 00:02:02,420 --> 00:02:08,100 A hotspot location is simply a celestial body, that is, a planet or a moon, that may have 32 00:02:08,100 --> 00:02:12,980 conditions that are conducive to the origin and existence of life. 33 00:02:12,980 --> 00:02:17,580 Scientists have located a number of potential hotspots in our solar system, though one of 34 00:02:17,580 --> 00:02:22,460 the most intriguing is a moon orbiting the planet Saturn named Titan. 35 00:02:22,460 --> 00:02:27,140 Titan is very exciting because unlike most moons in our solar system, it actually has 36 00:02:27,140 --> 00:02:28,140 an atmosphere. 37 00:02:28,140 --> 00:02:34,100 In fact, many scientists believe that Titan's atmosphere closely resembles early Earth's 38 00:02:34,100 --> 00:02:40,400 atmosphere three and a half billion years ago, when life was just beginning on our planet. 39 00:02:40,400 --> 00:02:45,500 The chemicals that make up Titan's thick, hazy atmosphere include nitrogen and carbon, 40 00:02:45,500 --> 00:02:50,660 elements considered by scientists to be the building blocks or raw materials for life 41 00:02:50,660 --> 00:02:51,940 as we know it. 42 00:02:51,940 --> 00:02:56,220 With this in mind, NASA and European Space Agency scientists are working on a mission 43 00:02:56,220 --> 00:03:02,220 called Cassini-Huygens, which will study Saturn and some of its moons, including Titan. 44 00:03:02,220 --> 00:03:07,300 The Huygens probe will descend into the thick Titan atmosphere to study its composition 45 00:03:07,300 --> 00:03:10,180 and look for signs of prebiotic chemistry. 46 00:03:10,180 --> 00:03:15,080 I spoke with Dr. Marianne Rotesel at NASA Langley Research Center to find out why this 47 00:03:15,080 --> 00:03:18,700 distant moon is such an important place to study. 48 00:03:18,700 --> 00:03:21,620 Titan's a really interesting place to explore for a number of reasons. 49 00:03:21,620 --> 00:03:22,980 It's a very large moon. 50 00:03:22,980 --> 00:03:27,860 It's larger than two of our planets, Mercury and Pluto, but the most interesting thing 51 00:03:27,860 --> 00:03:32,780 about it actually is that Titan has a very dense atmosphere, and this atmosphere has 52 00:03:32,780 --> 00:03:36,420 a lot of chemistry, interesting chemistry going on. 53 00:03:36,420 --> 00:03:40,100 Most of the atmosphere at Titan is nitrogen, a lot like Earth's. 54 00:03:40,100 --> 00:03:48,100 It has methane, but it also has a lot of complex organic types of molecules going on, and it 55 00:03:48,100 --> 00:03:49,300 has weather as well. 56 00:03:49,860 --> 00:03:56,260 We think that potentially there are actually clouds on Titan that kind of rain organic 57 00:03:56,260 --> 00:04:01,340 molecules down onto the surface and kind of lay out an organic sludge along the surface 58 00:04:01,340 --> 00:04:03,420 of Titan. 59 00:04:03,420 --> 00:04:10,060 A lot of scientists believe that in some important ways, Titan might actually be very much like 60 00:04:10,060 --> 00:04:15,140 what Earth was like in its early days prior to life on our planet, so it's an interesting 61 00:04:15,140 --> 00:04:20,780 place to go to kind of look at those processes and understand how life originated on our 62 00:04:20,780 --> 00:04:23,540 planet in that type of physical environment. 63 00:04:23,540 --> 00:04:27,660 One of the reasons Titan is of great interest to scientists is because it's the only moon 64 00:04:27,660 --> 00:04:32,860 in the solar system known to have clouds and a thick, planet-like atmosphere. 65 00:04:32,860 --> 00:04:37,540 Because Titan's atmosphere contains nitrogen and high percentages of smog-like chemicals 66 00:04:37,540 --> 00:04:43,660 such as methane and ethane, it may actually rain gasoline-like liquids onto the surface, 67 00:04:43,660 --> 00:04:46,420 forming shallow, methane-filled lakes. 68 00:04:46,420 --> 00:04:50,540 Although the smog-like atmosphere would be harmful to humans and other forms of complex 69 00:04:50,540 --> 00:04:56,580 life on our planet, the organic nature of Titan's atmosphere is much like the prebiotic 70 00:04:56,580 --> 00:04:59,620 environment from which life arose here on Earth. 71 00:04:59,620 --> 00:05:04,660 Simply put, these conditions may actually be laying the foundation for life on Titan 72 00:05:04,660 --> 00:05:05,980 sometime in the future. 73 00:05:05,980 --> 00:05:09,140 Dr. O'Donnell, is there potential for life on Titan? 74 00:05:09,620 --> 00:05:14,300 Well, that's a really interesting question, actually, and maybe yes and maybe no. 75 00:05:14,300 --> 00:05:16,860 And I say that because of this. 76 00:05:16,860 --> 00:05:21,660 Maybe yes, because Titan has, as I said, some really interesting and complex organic chemistry 77 00:05:21,660 --> 00:05:22,660 going on. 78 00:05:22,660 --> 00:05:28,100 But the problem is that chemistry isn't all that it takes to have life. 79 00:05:28,100 --> 00:05:32,100 Titan is very far away from our sun, and so it's a very, very cold place. 80 00:05:32,100 --> 00:05:35,640 So the problem is that everything is ice. 81 00:05:35,640 --> 00:05:39,960 And life, as we know, it needs access to liquid water. 82 00:05:39,960 --> 00:05:43,000 And it also needs a source of energy. 83 00:05:43,000 --> 00:05:50,040 So on the one hand, yes, the chemistry could potentially support early life on Titan, but 84 00:05:50,040 --> 00:05:51,040 it's not warm enough. 85 00:05:51,040 --> 00:05:56,040 It's too cold, and it doesn't have access to water and energy that it would need. 86 00:05:56,040 --> 00:06:02,160 But you could speculate about some other ways, perhaps, that it could have liquid water. 87 00:06:02,160 --> 00:06:08,160 We know, for example, that meteorites have come to Titan and hit the surface, generating 88 00:06:08,160 --> 00:06:10,320 heat and bringing energy with it. 89 00:06:10,320 --> 00:06:13,560 And perhaps for certain amounts of time, then that would mean that there could be pools 90 00:06:13,560 --> 00:06:14,880 of liquid water there. 91 00:06:14,880 --> 00:06:18,880 So it's really interesting to think about and speculate about the possibility of life 92 00:06:18,880 --> 00:06:22,240 in other parts and other locations of our solar system. 93 00:06:22,240 --> 00:06:26,360 And Titan is a very interesting place to look into those questions, and that's why we're 94 00:06:26,360 --> 00:06:27,360 going there. 95 00:06:27,360 --> 00:06:30,720 Once the spacecraft gets to Saturn, how will it collect data? 96 00:06:30,720 --> 00:06:32,880 Will it use rovers like the Mars rovers? 97 00:06:32,880 --> 00:06:36,800 No, actually, it's going to be rather different from the Mars mission. 98 00:06:36,800 --> 00:06:39,480 We're not sending rovers like Spirit and Opportunity. 99 00:06:39,480 --> 00:06:43,040 It won't be trundling around on the surface like we did on Mars. 100 00:06:43,040 --> 00:06:47,440 First, we're sending the Cassini spacecraft, and it's an orbiter. 101 00:06:47,440 --> 00:06:52,720 And when it reaches Saturn, it'll actually spend the next four years there kind of doing 102 00:06:52,720 --> 00:06:57,840 a grand tour through a Saturn system. 103 00:06:57,960 --> 00:07:04,360 And one of the things it will do is about 40 flybys near Titan and collect information, 104 00:07:04,360 --> 00:07:06,800 kind of a big-picture view of Titan. 105 00:07:06,800 --> 00:07:12,080 But then in addition to that, we have a Titan probe, Sliggen's probe, and that was developed 106 00:07:12,080 --> 00:07:13,880 by the European Space Agency. 107 00:07:13,880 --> 00:07:19,440 And it'll drop down through Titan's dense atmosphere, and all the way down, the instruments 108 00:07:19,440 --> 00:07:25,600 will be taking all kinds of measurements like the density of the atmosphere and the temperature 109 00:07:25,600 --> 00:07:27,560 and altitude and things of that sort. 110 00:07:27,560 --> 00:07:33,000 And of course, it's going to be taking a lot of data, a lot of information about the chemistry 111 00:07:33,000 --> 00:07:37,560 of Titan's atmosphere, what kinds of things are there and how much. 112 00:07:37,560 --> 00:07:41,400 And it'll take about two to two and a half hours to get all the way down through a dense 113 00:07:41,400 --> 00:07:42,560 atmosphere. 114 00:07:42,560 --> 00:07:47,600 We don't know what it will land in, but it will be able to stay on the surface and then 115 00:07:47,600 --> 00:07:52,520 in its local area kind of take some measurements and also radio that information back to the 116 00:07:52,520 --> 00:07:53,920 orbiter and back to Earth. 117 00:07:56,600 --> 00:08:01,680 The next generation of science missions to Titan will probably be much different than 118 00:08:01,680 --> 00:08:03,280 the missions of today. 119 00:08:03,280 --> 00:08:08,160 Because little is known about the moon's geology, one type of mission concept recently developed 120 00:08:08,160 --> 00:08:13,280 by NASA would rely on a dirigible-type craft to move through Titan's atmosphere, taking 121 00:08:13,280 --> 00:08:15,440 multiple measurements over time. 122 00:08:15,440 --> 00:08:21,760 This blimp would float above the surface and deploy a small probe to sample Titan's atmosphere, 123 00:08:21,760 --> 00:08:25,040 methane crater lakes, and crater rim ice. 124 00:08:25,040 --> 00:08:29,440 The probe would be able to analyze the samples on the spot and then relay the information 125 00:08:29,440 --> 00:08:31,360 to scientists back on Earth. 126 00:08:31,360 --> 00:08:36,120 With Earth nearly 800 million miles away, the probe would need to be almost completely 127 00:08:36,120 --> 00:08:37,120 autonomous. 128 00:08:48,000 --> 00:08:52,520 This type of craft could conceivably float through Titan's atmosphere for many months, 129 00:08:52,520 --> 00:08:57,320 gathering valuable evidence about Titan's chemistry and geology and what that means 130 00:08:57,320 --> 00:08:58,840 for us back on Earth. 131 00:09:22,520 --> 00:09:28,760 NASA Jet Propulsion Laboratory, California Institute of Technology 132 00:09:53,480 --> 00:09:56,280 Realistically, what are your expectations? 133 00:09:56,280 --> 00:09:59,080 Are you expecting to find life on Titan? 134 00:09:59,080 --> 00:10:04,280 Scientists try to be very objective, you know, and only have attitudes and opinions based 135 00:10:04,280 --> 00:10:06,840 upon what we know, of course. 136 00:10:06,840 --> 00:10:12,840 And so I think a lot of people are holding back and saying, I don't expect to find life 137 00:10:12,840 --> 00:10:13,840 there. 138 00:10:13,840 --> 00:10:14,840 It's too cold. 139 00:10:14,840 --> 00:10:18,560 Even though we have extremophiles here on our planet that can live in very dry or very 140 00:10:18,720 --> 00:10:23,200 cold conditions, it's really cold out there, you know, and there isn't liquid water. 141 00:10:23,200 --> 00:10:25,440 So we're not expecting to see anything there. 142 00:10:25,440 --> 00:10:30,320 But the nice thing would be is if we could find, I think a lot of people would be very, 143 00:10:30,320 --> 00:10:35,120 very happy if we saw some serious complex organic chemistry going on. 144 00:10:35,120 --> 00:10:40,840 Prebiotic, you know, clearly prebiotic chemistry would just be wonderful. 145 00:10:40,840 --> 00:10:45,600 Going to other destinations in our solar system and then gathering this kind of information 146 00:10:45,760 --> 00:10:54,160 can really help us understand how our planet formed and how life originated on our planet. 147 00:10:54,160 --> 00:10:58,800 And these were really profound questions, not just to scientists, but to everyone. 148 00:10:58,800 --> 00:11:05,160 And so I think it's really interesting and great that NASA can send spacecraft and gather 149 00:11:05,160 --> 00:11:12,640 these kinds of data to help us answer those kinds of questions. 150 00:11:12,640 --> 00:11:17,600 Many astrobiologists are skeptical as to whether life as we know it exists on Titan. 151 00:11:17,600 --> 00:11:21,560 Although many of the building blocks for life are there, temperatures average a numbing 152 00:11:21,560 --> 00:11:24,240 minus 290 degrees Fahrenheit. 153 00:11:24,240 --> 00:11:29,040 However, Titan might provide a habitat for life if scattered sources of heat from geysers 154 00:11:29,040 --> 00:11:31,360 or volcanoes are discovered. 155 00:11:31,360 --> 00:11:35,840 Coming up, we'll find out how NASA has been using a technique called aerobraking to insert 156 00:11:35,840 --> 00:11:38,640 spacecraft into extraplanetary orbits. 157 00:11:38,640 --> 00:11:43,120 But first, did you know that Saturn's density is the lowest in the solar system? 158 00:11:43,120 --> 00:11:48,320 Although Saturn has a diameter of about 75,000 miles, it's made up of primarily hydrogen 159 00:11:48,320 --> 00:11:50,000 and helium gases. 160 00:11:50,000 --> 00:11:55,200 The presence of these gases makes Saturn's specific gravity at about 0.7, less than that 161 00:11:55,200 --> 00:11:56,200 of water. 162 00:11:56,200 --> 00:12:01,120 In fact, Saturn's density is so low that if it were placed in an imaginary gigantic 163 00:12:01,120 --> 00:12:05,200 bathtub, it would float.