1 00:00:00,012 --> 00:00:08,061 Hello, and welcome. I'm Charles Cockell, Professor of 2 00:00:08,061 --> 00:00:18,670 Astrobiology at the University of Edinburgh. And thanks for taking this 3 00:00:18,670 --> 00:00:25,753 course, Introduction Astrobiology. Astrobiology is a very new, exciting, and 4 00:00:25,753 --> 00:00:30,686 a very rapidly developing area of science that addresses the question of the 5 00:00:30,686 --> 00:00:35,212 origin, the evolution, and the distribution of life in the universe. 6 00:00:35,212 --> 00:00:39,929 There's little doubt in saying that one of the most exciting questions in 7 00:00:39,929 --> 00:00:44,808 Astrobiology Is are we alone in the universe? And I should say right at the 8 00:00:44,808 --> 00:00:49,787 beginning of this course we don't have an answer to this question, but we do know 9 00:00:49,787 --> 00:00:54,189 that the answer is either yes or no. And either one of those answers has 10 00:00:54,189 --> 00:00:58,397 profound implications for our understanding of our own place in the 11 00:00:58,397 --> 00:01:01,501 universe. If the answer to this question is yes we 12 00:01:01,501 --> 00:01:05,462 are alone in the universe, then we need to ask the question. 13 00:01:05,462 --> 00:01:10,061 While we are learning the universe. What is missing on other planets that was 14 00:01:10,061 --> 00:01:14,660 present on Earth and allowed life to originate and evolve here? We would have 15 00:01:14,660 --> 00:01:19,020 to find out about the origin and the evolution of life on Earth in order to 16 00:01:19,020 --> 00:01:23,665 find out why life on Earth is so special. It would also raise fundamental 17 00:01:23,665 --> 00:01:27,961 philosophical questions. If there's no other life in the rest of 18 00:01:27,961 --> 00:01:30,875 the universe there's no one else to talk to. 19 00:01:30,875 --> 00:01:35,492 Then why have we spent the last 40,000 years building a civilization. 20 00:01:35,492 --> 00:01:41,156 Is it just so we can be lonely in greater luxury? Astrobiology forces us to Address 21 00:01:41,156 --> 00:01:46,307 philosophical questions that strike at the very core of our civilization. 22 00:01:46,307 --> 00:01:51,506 If the answer to this question is no, we're not alone in the universe, we're 23 00:01:51,506 --> 00:01:54,940 also faced with some very fascinating questions. 24 00:01:54,940 --> 00:02:00,569 What is the nature of this other life on other planets? Is it microbial life? Life 25 00:02:00,569 --> 00:02:05,472 like bacteria and if so how does it compare to life on earth and where is it? 26 00:02:05,472 --> 00:02:10,496 Or is it intelligent life? And if it is intelligent life what is the nature of 27 00:02:10,496 --> 00:02:14,909 this other intelligence. Can we communicate with it, and what will 28 00:02:14,909 --> 00:02:18,152 be the consequences if we do communicate with it. 29 00:02:18,152 --> 00:02:21,782 All that we know in the universe is unquestionably. 30 00:02:21,782 --> 00:02:26,847 The, the one question in astro biology that fires the imagination of the general 31 00:02:26,847 --> 00:02:29,637 public. And it's probably the question that 32 00:02:29,637 --> 00:02:34,187 brought you along to this course. It's a very reasonable question to ask 33 00:02:34,187 --> 00:02:37,332 when you think about the universe that we live in. 34 00:02:37,332 --> 00:02:41,542 The planet on which we live orbits a single star, and this star. 35 00:02:41,542 --> 00:02:45,721 Is one of about 200 billion stars in the Milky Way galaxy. 36 00:02:45,721 --> 00:02:51,672 And our own galaxy is probably one many, many billions of galaxies throughout the 37 00:02:51,672 --> 00:02:55,366 universe. In truth we don't know how many galaxies 38 00:02:55,366 --> 00:03:00,087 there are in the universe. It may be something on the order of 100 39 00:03:00,087 --> 00:03:05,136 billion galaxies, maybe more. But if you think about it, 200 billion 40 00:03:05,136 --> 00:03:09,258 stars in our own galaxy. Possibly a 100,000,000,000 galaxies 41 00:03:09,258 --> 00:03:13,366 throughout the universe. It seems reasonable to ask the question, 42 00:03:13,366 --> 00:03:18,322 is there life on other planets? And, that is why astrobiologist concerned with a 43 00:03:18,322 --> 00:03:22,727 question for which we do not yet have an answer but which scientifically 44 00:03:22,727 --> 00:03:26,092 impirically looks like a reasonable question to ask. 45 00:03:26,092 --> 00:03:31,249 To search for life on other planets, we first of all have to understand something 46 00:03:31,249 --> 00:03:36,431 about life on our own home planet Earth. This is a rather beautiful image taken by 47 00:03:36,431 --> 00:03:41,066 the Apollo 11 astronauts on the surface of the Moon and it shows the Earth 48 00:03:41,066 --> 00:03:46,031 hovering above the horizon of the Moon. It's sometimes called the blue marble 49 00:03:46,031 --> 00:03:49,208 image. Because it shows a picture of the earth 50 00:03:49,208 --> 00:03:53,183 as a tranquil planet. It looks like a very peaceful place but 51 00:03:53,183 --> 00:03:58,280 this belies the history of life on earth and the future of life on this planet. 52 00:03:58,280 --> 00:04:03,352 For example, we know that planet earth has been struck by large pieces of rock 53 00:04:03,352 --> 00:04:06,751 in it's past. Asteroid and comet impact that have done 54 00:04:06,751 --> 00:04:10,062 devastating things to life on the surface of the earth. 55 00:04:10,062 --> 00:04:14,818 We think, for example, that the dinosaurs were made extinct by such an asteroid 56 00:04:14,818 --> 00:04:19,037 impact 65,000,000 years ago. Now, whether an asteroid really did kill 57 00:04:19,037 --> 00:04:22,339 the dinosaurs. It's something that's controversial in 58 00:04:22,339 --> 00:04:27,079 some parts of the scientific community, but whatever one views about The fact 59 00:04:27,079 --> 00:04:31,222 that scientists purport that the extinction of the dinosaurs was caused by 60 00:04:31,222 --> 00:04:35,526 an asteroid shows that, for in order to understand the past history of life on 61 00:04:35,526 --> 00:04:39,694 earth, we have to understand it's connection with the cosmic environment. 62 00:04:39,694 --> 00:04:43,998 What sort of rocks might come from outer space and threaten life on the earth. 63 00:04:43,998 --> 00:04:48,914 So, to undrstand past history of life on earth, we have to understand Astropology, 64 00:04:48,914 --> 00:04:51,695 how life fits in to its cosmic environment. 65 00:04:51,695 --> 00:04:55,762 We also know that the future of life on earth is going to change. 66 00:04:55,762 --> 00:05:00,706 This is a rather dramatic image of the cloud Nebula, the result of a supernova 67 00:05:00,706 --> 00:05:05,124 explosion, an exploding star which exploded thousands of years ago. 68 00:05:05,124 --> 00:05:09,452 Our own Sun may not end its life in quite such a dramatic matter. 69 00:05:09,452 --> 00:05:14,240 But in a few billion years from now sun will come to the end of it's life and at 70 00:05:14,240 --> 00:05:18,744 that point our own planet will be completely destroyed and all life on will 71 00:05:18,744 --> 00:05:22,218 be extinguished. That's not for a long time to come but we 72 00:05:22,218 --> 00:05:26,921 do know that in order to understand the future of life on a planet. 73 00:05:26,921 --> 00:05:30,396 Its long term future. We must think about the connection of a 74 00:05:30,396 --> 00:05:33,015 planet. Again, with its cosmic environment. 75 00:05:33,015 --> 00:05:35,999 How it connects with the history of its parent star. 76 00:05:35,999 --> 00:05:39,902 And how long that star lives. And therefore, how long you can expect 77 00:05:39,902 --> 00:05:43,830 life to survive on a planet. So in order to understand life on Earth, 78 00:05:43,830 --> 00:05:48,514 we have to understand the past history of life, and its connection with the cosmic 79 00:05:48,514 --> 00:05:51,182 environment. And we have to understand. 80 00:05:51,182 --> 00:05:56,012 The future of life on earth and it's connection with the cosmic environment. 81 00:05:56,012 --> 00:06:00,702 In other words, an understanding of life on earth is really about studying 82 00:06:00,702 --> 00:06:06,067 astrobiology, the connection of life with it's astronomical or cosmic environment. 83 00:06:06,067 --> 00:06:10,712 So astrobiology has many areas that we will look at in this course and many 84 00:06:10,712 --> 00:06:15,092 questions that it wants to address. Let's have a look at some of these 85 00:06:15,092 --> 00:06:18,982 questions, and see what we're going to look at throughout this course. 86 00:06:18,982 --> 00:06:23,302 Astrobiology is first interested with understanding the origin of life on this 87 00:06:23,302 --> 00:06:25,882 planet. How did it come about? And the sorts of 88 00:06:25,882 --> 00:06:30,684 questions that astrobiologists ask, and that we'll be looking at in this course, 89 00:06:30,684 --> 00:06:35,894 how did life originate on this planet? Where did life originate? What were the 90 00:06:35,894 --> 00:06:40,906 locations of the first organisms to emerge on this planet? Where might they 91 00:06:40,906 --> 00:06:45,869 have first evolved? Is life an inevitable process? On any planet where the 92 00:06:45,869 --> 00:06:50,956 conditions are good enough, do you always get an evolution of life? Is this a 93 00:06:50,956 --> 00:06:56,882 common process? Throughout the universe. When did this happen? Did it happen very 94 00:06:56,882 --> 00:07:02,133 quickly after the Earth was formed or did it take rather a long time for those 95 00:07:02,133 --> 00:07:06,104 chemical reactions to lead to the earliest types of life. 96 00:07:06,104 --> 00:07:11,586 And what is the evidence for the origin of life on this planet and it's emergence 97 00:07:11,586 --> 00:07:17,045 into early single cell organisms that first occupied this planet many billions 98 00:07:17,045 --> 00:07:22,110 of years ago? Once we've established the presence of life on a plant we want to 99 00:07:22,110 --> 00:07:25,655 know its limits. How far can you push it and what sort of 100 00:07:25,655 --> 00:07:29,555 extremes can it live in. This is important if we're to try and 101 00:07:29,555 --> 00:07:34,825 understand the possibilities of life on other planets to access that habitability 102 00:07:34,825 --> 00:07:37,727 as we call it. And the sorts of questions that 103 00:07:37,727 --> 00:07:42,861 astrobiologists want to address are. What are the limits of life? What are the 104 00:07:42,861 --> 00:07:47,735 most extreme physical and chemical environments that life can survive and 105 00:07:47,735 --> 00:07:53,051 grow in? How does life survive extremes? What are the sorts of mechanisms that it 106 00:07:53,051 --> 00:07:58,609 involves? What sort of biochemistry, what sort of physiology do organisms evolve in 107 00:07:58,609 --> 00:08:04,012 order to be able to cope with some of the most extreme environments on the earth? 108 00:08:04,012 --> 00:08:08,793 And are these limits universal? If we do find life on another planet out there in 109 00:08:08,793 --> 00:08:13,392 the universe, will it be living in completely conditions from life on Earth? 110 00:08:13,392 --> 00:08:17,992 Or will we in fact find similar life living in similar types of environments. 111 00:08:17,992 --> 00:08:22,267 And once we've looked at life in extremes what does that tell us about the 112 00:08:22,267 --> 00:08:26,662 prospects of life elsewhere, about the possibilities for going to extreme 113 00:08:26,662 --> 00:08:31,392 environments on other planets and finding life there? So by studying life on our 114 00:08:31,392 --> 00:08:35,732 planet today and looking at the way in which it lives in different types of 115 00:08:35,732 --> 00:08:40,069 environments and different extremes. We can learn something about the 116 00:08:40,069 --> 00:08:44,771 prospects for life elsewhere. Astrobiology, as I've already mentioned, 117 00:08:44,771 --> 00:08:49,356 is also concerned with trying to understand the history of life on Earth 118 00:08:49,356 --> 00:08:52,935 once it did emerge. It's concerned with questions like, how 119 00:08:52,935 --> 00:08:57,365 is life related? When you walk around outside you see a whole diversity of life 120 00:08:57,365 --> 00:09:01,286 from dogs to giraffes to trees. How are all these different creatures 121 00:09:01,286 --> 00:09:05,580 related and how do they come to be on the surface of the earth and how did they 122 00:09:05,580 --> 00:09:10,062 evolve? Astrobiology is interested in trying to understand the connection 123 00:09:10,062 --> 00:09:14,828 Between these different creatures and how they came to be and evolve from one 124 00:09:14,828 --> 00:09:18,622 another over time. We also want to know about multi-cellular 125 00:09:18,622 --> 00:09:22,397 life, complex life. We'll see later in this course that when 126 00:09:22,397 --> 00:09:27,238 you look around you most of the life that you and I are familiar with are things 127 00:09:27,238 --> 00:09:30,307 like. Dogs and giraffes that are multicellular 128 00:09:30,307 --> 00:09:34,846 creatures, complex large organisms that we can see with the naked eye. 129 00:09:34,846 --> 00:09:39,719 But in fact much of life on Earth is bacteria, archaea, simple single celled 130 00:09:39,719 --> 00:09:42,262 organisms. And we want to understand as 131 00:09:42,262 --> 00:09:47,319 astrobiologists how life emerged from those more simple organisms in the early 132 00:09:47,319 --> 00:09:51,887 history of life on Earth, to the more complex life that you and I see on a 133 00:09:51,887 --> 00:09:55,121 day-to-day basis. On the surface of the planet. 134 00:09:55,121 --> 00:09:59,748 And another question that concerns astrobiologists is catastrophes and 135 00:09:59,748 --> 00:10:03,076 extinctions. How does life go extinct? How do these 136 00:10:03,076 --> 00:10:08,346 catastrophes affect life throughout its history whether that be asteroid or comet 137 00:10:08,346 --> 00:10:13,428 impacts, giant volcanic eruptions, and what sort of catastrophes might befall 138 00:10:13,428 --> 00:10:18,509 life along its long tenure of life on earth? Astrobiology is concerned with 139 00:10:18,509 --> 00:10:22,142 taking this information and looking for life elsewhere. 140 00:10:22,142 --> 00:10:27,203 And as I said earlier there's no doubt that this is most interesting question in 141 00:10:27,203 --> 00:10:30,790 astrobiology. At least the one that captures the public 142 00:10:30,790 --> 00:10:33,688 imagination. And the sorts of questions that 143 00:10:33,688 --> 00:10:38,795 astrobiologists ask once they begin to get an understanding of life on the Earth 144 00:10:38,795 --> 00:10:41,680 is. Is there life elsewhere in the universe? 145 00:10:41,680 --> 00:10:46,385 Are we a unique experiments in biological evolution or is it repeated on other 146 00:10:46,385 --> 00:10:51,349 planets? And if there is life elsewhere, what does it look like? What sort of life 147 00:10:51,349 --> 00:10:55,861 is it? Is it microbial life, single celled life or is it intelligent life? 148 00:10:55,861 --> 00:11:01,098 And if there isn't any life out there in the universe Why not? What's missing in 149 00:11:01,098 --> 00:11:06,231 the rest of the Universe that was present on the Earth that allowed life to 150 00:11:06,231 --> 00:11:11,935 originate and evolve on this planet? Of course, following on from that question, 151 00:11:11,935 --> 00:11:16,962 another interest for Astropology but certainly for the general public. 152 00:11:16,962 --> 00:11:19,921 Is, are there other intelligences in the universe. 153 00:11:19,921 --> 00:11:23,207 If there is life out there, could it be intelligent life. 154 00:11:23,207 --> 00:11:27,060 And the source of questions that astrologist want to address is, is 155 00:11:27,060 --> 00:11:30,762 intelligence inevitable. Whereever we get life on a planet is it 156 00:11:30,762 --> 00:11:34,943 inevitable that it will eventually progress to intelligent types of life 157 00:11:34,943 --> 00:11:37,674 forms. Can we communicate with life on other 158 00:11:37,674 --> 00:11:42,362 planets, and if we do communicate with it, what would be the consequences for 159 00:11:42,362 --> 00:11:44,957 society. What would happen to us if we made 160 00:11:44,957 --> 00:11:49,545 contact with another intelligences. How would that affect religion and our 161 00:11:49,545 --> 00:11:54,352 social structures, and we'll answer some of those questions in this course. 162 00:11:54,352 --> 00:11:59,551 Of course it's all very well looking for alien life and studying the evolution of 163 00:11:59,551 --> 00:12:03,379 life on the earth and going out hunting for life elsewhere. 164 00:12:03,379 --> 00:12:08,481 But of course we may eventually ourselves leave the Earth and travel beyond and 165 00:12:08,481 --> 00:12:12,765 establish permanent settlements on places Like the moon and Mars. 166 00:12:12,765 --> 00:12:17,353 And astrobiology is also concerned with the technical question of how human 167 00:12:17,353 --> 00:12:20,007 beings will establish themselves in space. 168 00:12:20,007 --> 00:12:24,695 What is the future of human life beyond the Earth? The sorts of questions that 169 00:12:24,695 --> 00:12:29,149 astrobiologists are concerned with span from science, to technology, to 170 00:12:29,149 --> 00:12:32,895 philosophy and these. Sorts of questions are things like will 171 00:12:32,895 --> 00:12:37,585 humans leave the Earth? Is it inevitable that we will move out beyond the Earth 172 00:12:37,585 --> 00:12:42,473 and establish a permanent human presence beyond our home planet? And if we do make 173 00:12:42,473 --> 00:12:46,635 this choice to leave the Earth how will we do it? How will we establish 174 00:12:46,635 --> 00:12:51,343 self-sustaining settlements on other planets? And if we are going to spend 175 00:12:51,343 --> 00:12:56,335 money and human resources establishing, other branches of civilization, beyond 176 00:12:56,335 --> 00:13:01,069 the earth on other planets, how do we do that but at the same time preserve the 177 00:13:01,069 --> 00:13:05,642 earth? How do we look after our own planet, live sustainably on the earth, 178 00:13:05,642 --> 00:13:09,362 but establish sustainable settlements on other planets. 179 00:13:09,362 --> 00:13:12,303 And planetary bodies such as the Moon and Mars. 180 00:13:12,303 --> 00:13:17,357 And how will we adapt to space if we move out beyond the what will be the social 181 00:13:17,357 --> 00:13:21,640 implications for humanity. How will we change as a species? How will 182 00:13:21,640 --> 00:13:26,519 our societies develop as we move out beyond the Earth and establish satellites 183 00:13:26,519 --> 00:13:31,372 on other planetary bodies? These are just some of the questions, some of the 184 00:13:31,372 --> 00:13:34,488 Diversity of questions that astrobiologists seek to ask. 185 00:13:34,488 --> 00:13:37,704 And in this course you're going to learn a number of things. 186 00:13:37,704 --> 00:13:41,426 You're going to learn about basic concepts that underpin the study of 187 00:13:41,426 --> 00:13:45,372 astrobiology, some of the questions that I've just described to you. 188 00:13:45,372 --> 00:13:50,144 We're going to learn about some of the history of life on our home planet, how 189 00:13:50,144 --> 00:13:54,590 it originated, how it evolved. We're going to learn about how we search 190 00:13:54,590 --> 00:13:59,432 for life on other planets, how we use our knowledge of life on the earth to go. 191 00:13:59,432 --> 00:14:03,965 Beyond the Earth and send out missions to Mars and other planets and seek out 192 00:14:03,965 --> 00:14:06,739 signatures of life on other planetary bodies. 193 00:14:06,739 --> 00:14:11,429 We're going to look a little bit about the future of human life beyond the Earth 194 00:14:11,429 --> 00:14:15,400 and the establishment of a permanent human presence beyond Earth. 195 00:14:15,400 --> 00:14:18,942 We're going to look at some of these social implications. 196 00:14:18,942 --> 00:14:22,304 Of astrobiology. More difficult to define than some of the 197 00:14:22,304 --> 00:14:26,611 scientific research associated with astrobiology, but never the less very 198 00:14:26,611 --> 00:14:30,817 important for understanding the way in which science can affect society. 199 00:14:30,817 --> 00:14:34,407 And the way in which we think about The Universe around us. 200 00:14:34,407 --> 00:14:38,426 We're also going to look at the difference between science and 201 00:14:38,426 --> 00:14:42,085 sensationalism. And you may have noticed that in some of 202 00:14:42,085 --> 00:14:47,309 the publicity for this course, there was even talk about UFOs, alien autopsies, 203 00:14:47,309 --> 00:14:52,702 and all sorts of crazy, but never the less, interesting material that captures 204 00:14:52,702 --> 00:14:57,109 the imagination of many people. And in this course, we want to learn 205 00:14:57,109 --> 00:14:59,067 about. What is empirical size. 206 00:14:59,067 --> 00:15:02,982 What is evidence that allows us to address scientific questions of 207 00:15:02,982 --> 00:15:06,287 astrobiology. On more areas of astrobiology and not are 208 00:15:06,287 --> 00:15:10,512 depend at the moment by any empirical evidence that make it difficult to 209 00:15:10,512 --> 00:15:14,622 address particular questions. Astrobiology is a very good vehicle. 210 00:15:14,622 --> 00:15:18,918 Particularly when we talk about extraterrestrial intelligences, so 211 00:15:18,918 --> 00:15:23,653 thinking about the difference between science and sensationalism and we'll 212 00:15:23,653 --> 00:15:27,284 touch upon some of those problems throughout this course. 213 00:15:27,284 --> 00:15:32,277 So what have we learnt in this brief introduction to astrobiology? Hopefully 214 00:15:32,277 --> 00:15:36,097 what you've learnt is that astrobiology covers many fields. 215 00:15:36,097 --> 00:15:40,227 It's a very diverse subject. It goes from physics, to chemistry, 216 00:15:40,227 --> 00:15:44,447 biology, and even philosophy and sociology when we think about the 217 00:15:44,447 --> 00:15:47,542 implications of discoveries in astrobiology. 218 00:15:47,542 --> 00:15:50,887 Astrobiology is a subject as its name suggests. 219 00:15:50,887 --> 00:15:54,466 Astrobiology that sets life in its cosmic context. 220 00:15:54,466 --> 00:15:59,340 It seeks to understand how life on a planet evolves in the context with 221 00:15:59,340 --> 00:16:05,171 changing astronomical environment, and how life changes through Its origin, its 222 00:16:05,171 --> 00:16:10,095 evolutional planet, and eventually the end of that planet as its destroyed 223 00:16:10,095 --> 00:16:14,458 perhaps by its parent star. Astrobiology seeks to understand life 224 00:16:14,458 --> 00:16:19,870 from how it arose to how intelligent life might one day colonise other planets from 225 00:16:19,870 --> 00:16:23,142 Earth possibly to the Moon and Mars and beyond. 226 00:16:23,142 --> 00:16:28,372 And as you'll see throughout this course, Astrobiology, as well as being a science 227 00:16:28,372 --> 00:16:32,992 in its own right, is actually an outstanding vehicle for learning many of 228 00:16:32,992 --> 00:16:37,092 the common principles that underpin different parts of science. 229 00:16:37,092 --> 00:16:41,852 It's a way to learn about different disciplines as well as to understand the 230 00:16:41,852 --> 00:16:46,785 possibility of the origin, evolution and distribution of life in the universe.