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00:00The search for life beyond our earth is a daunting prospect and yet the signs of
00:07building blocks are everywhere. I can't say for sure because we've only got the
00:12one example of life on earth to work with so far but all the ingredients are
00:17out there. Solar systems make everything you need for life insofar as we know.
00:23So it could be that matter naturally organizes itself into into life.
00:33Within our solar system we are studying all the places where life might well
00:38evolve. Mars for example once had two of the essentials free-flowing water and
00:44volcanoes. Then there are the ice moons of the giant planets Europa and Ganymede
00:50with their internal oceans. Even the far-flung Pluto has shown some
00:54interesting signs. There is however only one ideal environment in our solar system
01:00Earth. To find other such oases we must look for exoplanets around other star
01:07systems. A very difficult challenge.
01:20Well there's sort of two things that are driving the places that we look for exoplanets. The
01:39planetary systems where we'd most like to be able to find planets just like our own that
01:45orbit at just the right distance from their host star to potentially be able to
01:49host life are orbiting stars just like our own. They're what are known as G-type stars.
01:55But the difficulty is that the distance that a planet orbits around one of those
02:01stars with a period of around one year means that the signatures for seeing those
02:07planets are really really small. So they're incredibly technically challenging to find
02:13planets around sun-like stars. So the next best category. The sorts of systems that we're
02:18putting a lot of effort into are stars that are much smaller than the Sun. About a tenth the
02:25size of the Sun. You get a type of star that's called an M dwarf. It's very red. It's very faint.
02:30And as a result the distance where you get the same amount of flux as you get from the Sun
02:35shrinks in to about the orbit of Mercury or inside the orbit of Mercury. And that makes the signatures
02:44for detecting that planet much easier to find. And so there's a lot of effort going into looking for
02:50what we call habitable zone planets around these small M dwarf stars.
02:55There are two basic ways that we can find planets around other stars. And both of them look for the
03:10indirect effect of the planet on the star. We don't see the planet itself. We see that what the planet does
03:16to the star. And we either see the planet orbiting within the line of sight and crossing the disk of
03:23the star and making it a little bit dimmer. Those are what are called transit planets. Or we see the
03:29planet orbiting around the star and making the star move backwards and forwards along the line of sight.
03:34And we can measure the velocity of the star. Basically we use telescopes as giant speed guns to measure the
03:42star going backwards and forwards. And those are what are called Doppler detections of these planets.
03:47And for transit searches finding multiple planets is a lot easier. Most of the multiple planet systems
03:55we've found have come from space-based transit searches like the Kepler mission. For Doppler searches
04:02finding the subsequent planets gets harder and harder and harder as you go to larger and larger separations
04:08systems from the star. The wobble signature of the star moving backwards and forwards gets smaller
04:13and it gets progressively harder and harder to find.
04:16So what we found is that there are lots and lots of multi-planet systems out there. I don't know that it's true
04:32that they're less or more common than we at first thought. They're certainly they require more intensive
04:40observations when you're looking for a planet around another star. The first planet you find is the
04:46easiest planet to find and then finding the subsequent planets usually involves getting more and more and
04:52more data so that you can see the usually the much smaller signal on maybe a longer period that tells you
04:59there's another planet and then once you found those two if you want to find the subsequent one then
05:03you've got to get even more data to this end two new space observatories are soon to be launched TESS
05:16NASA's transiting exoplanet survey satellite designed to find planets crossing the face of their sun
05:22and the much lauded James Webb Space Telescope. It will be able to see and analyze the atmosphere
05:29of those distant planets.
05:41So we have four key contribution we are supplying two out of the four scientific instruments
05:47and we are responsible for the launch of James Webb from French Vienna with the ION-5 rocket
05:52and we also supply personnel for the operation of James Webb Space Telescope from from the Space Telescope
05:57Science Institute. So James Webb has been built to initially to see galaxies and when they form so
06:04these galaxies of these assembly of stars and we are trying to look at really the first 100 million
06:10years of the universe and look at their formation but at the end of the day it's going to do much more
06:15than that and in particular a very exciting field where it will do a lot of bring exciting results or exoplanets you know
06:23characterizing the atmosphere of planets orbiting all over stars that's really exciting.
06:31TESS and the James Webb Telescope will be ready for launch within the year and are expected to open
06:37up a whole new era of discovery.
06:46So there are the things we expect Webb to do such as see the very first stars and galaxies to light up
06:53after the big bang so we know we've designed it for that we expect it to do that additionally we expect
06:59that people will use it to study the atmospheres of exoplanets but as a scientist what I look for
07:05are those unique uses that no one has planned for because it's out of those unexpected discoveries
07:11that most of the excitement arises. To date there are over 3500 confirmed exoplanets double that again
07:20yet to be confirmed and of those over 360 are terrestrial planets some are even classed as super earths.
07:28The reason why the TESS mission is exciting compared to or in addition to Kepler is that Kepler has told us
07:39an enormous amount about the statistics of how many planets are present around stars so it tells us
07:50that the frequency of very small planets is quite common so planets on around about the sort of the
07:56size of the earth seem to exist around almost every star as far as we can see often in very short periods much
08:06too short to be habitable but they're relatively common but what it doesn't tell us about is the
08:16properties of those planets so because when you find a transit planet you're essentially seeing
08:22a dark thing moving across the disk of a bright thing the only thing that that transit detection
08:28tells you is about the period of the planet and the size of the planet is its physical radius what we
08:34really want to know is the size of the planet and its mass because if you know the size and the mass then
08:39you know the density and if you know the density you know whether it's a a gassy planet like jupiter or
08:45an icy planet like neptune or a rocky planet like the earth or venus or mars
09:01so before we found exoplanets before we found planets around other stars in 1995 everybody expected
09:16that planet formation elsewhere would produce systems that look just like our solar system
09:22and for about 20 years what we consistently found was thousands of planetary systems that look nothing
09:29like our solar system we've got gas giant planets that orbit inside the orbit of mercury you've got
09:36gas giant planets that orbit where venus earth and mars are you've got planets in highly eccentric orbits
09:43highly non-circular orbits almost all the orbits in our solar system are really quite circular
09:49most exoplanets most planets around other stars don't have those nice circular orbits
09:54planets we find system architectures that are very very different from our own which suggests that
10:01maybe uh the uh the structure of our own solar system is not uh the norm maybe it's uh unusual for
10:09reasons that we still don't understand
10:23planetary system even just the earth is an incredibly complex system uh and we are yet to understand the
10:32sort of multiplicity of what other planetary systems look like the other thing to bear in mind is that
10:39saying that other planetary systems should look like our own solar system is an incredibly risky assumption to make
10:55the variety of planets we are finding is indeed fascinating from hot gas giants of various sizes
11:01to terrestrials varying in dimension from moon size up to two or three times the size of earth
11:09the planet is so finding planets is hard it's really hard finding life is that much harder still
11:25at the moment the prime focus of most of the people who are looking for planets around other stars is
11:34not so much to look for signatures of life but for look for signatures of habitability that is an
11:40environment that is similar to what we see here on the earth so a roughly earth-sized planet uh at uh roughly the same sort of
11:42separation from its host star modulo the brightness of the star um and then potentially saying well can we see
11:59can we see the properties of the atmosphere can we see whether it's got water in it can we see whether it's
12:06um dominated by uh thick clouds of sulfuric acid like venus in which case it's probably not going to be
12:13habitable or has it got a relatively thin atmosphere like the earth's atmosphere is actually quite tenuous
12:19compared to the atmospheres of lots of uh planets so it's sort of finding out those properties that's
12:27even harder the next step is uh what are the signatures of life that you look for um do you look for
12:36uh methane emissions do you look for the signatures of um molecular oxygen so when the earth first formed
12:45there was no molecular oxygen in the atmosphere oxygen is a byproduct largely of life of the cyanobacteria
12:54that formed in the oceans very early earlier on so those are the sorts of signatures that you could
13:01try to look for a lot of that is sort of guesswork because we don't really know how life on our own
13:09earth got started um trying to guess what life on another planet would look like we're sort of limited
13:18to looking for something just like ourself there's no guarantee that the only pathway for uh for life is
13:26to look just like us the visible stars above us at night most likely all contain planets and not just
13:44one the keys to confirming these discoveries are highly sensitive spectrographs here on the ground
13:51like the european observatory that uses the extremely successful harps
14:07so that we're building a new facility to do the the doppler follow-up that i was talking about before
14:13you need very specialized pieces of equipment attached to very large telescopes to do this
14:19uh if you remember because planets are small stars are big uh the wobble that is produced by a planet
14:28going around a star is very small jupiter produces a wobble in velocity of about 12 meters a second
14:35so it makes the sun move at about the speed of hussein bolt uh and it does it with a period of around
14:42about 12 years now measuring the speed of hussein bolt sounds straightforward to do except that you're
14:47trying to do it around something that is extremely faint and somewhere between 50 and 100 parsecs away
14:54and so you're having to calibrate your system to extraordinary levels of precision that's to find
15:00an easy planet like jupiter if you want to find a tiny planet like the earth you've got to get down to
15:06precisions in the velocity that you're measuring of well below a meter per second and that's why we
15:11need to build specialized facilities to go on our telescopes like the veloce spectrograph which sits
15:18in a basically in a big box it's pressure controlled it's temperature controlled uh it's got a state of
15:25the art laser comb where we pulse a laser uh with extremely high precision to make a calibration signal
15:34to inject into it and you need a big telescope at least a four meter telescope like the anglo-australian
15:39telescope or bigger ones similar facilities are being built on eight meter class telescopes and larger
15:53so the european southern observatory have been running the harps spectrograph on their 3.6 meter
16:13telescope at the lycia observatory in chile for uh over 10 years now and it is again another one of these
16:21uh ultra stabilized uh very complex spectrographs we have adopted for veloce slightly different design
16:30strategies in a number of different ways because we have a different site and a different telescope
16:36but it is focused on very much the same sort of science and it along with us and a number of other
16:44facilities worldwide will be engaged in the big international endeavor of following up the results
16:51from tests one of the things that kepler taught us it found thousands of exoplanets and when they
16:59started that mission the follow-up programs were essentially limited to just the people who were in
17:05the tests science teams and they quickly found that there was not enough telescope time available to
17:12them and not enough telescopes in order to exploit the the treasure trove of data that came out of
17:19kepler so we've learned from that the test mission the data is essentially freely made available once it's
17:26been processed by the test team it's put on a website and then everybody around the world will be
17:33trying to coordinate but also trying to compete to to find the most interesting planets coming out of
17:40that the main point being that there is so much data even using all of the telescopes and all of
17:48the facilities available to us there will still be objects which don't get observed and don't get
17:53followed up so we and harps will be both competitors and collaborators in following up the results from
18:01tests and of course the interesting thing is that for almost the first time in the history of modern
18:06astronomy southern hemisphere chauvinism has been reversed so test is surveying the southern hemisphere
18:12first so we get first dibs on all of that data ahead of those northern hemisphere rights
18:24with the new technology about to come online the speed and success of planet finding and confirmation
18:30will increase considerably allowing us to better target the planets of most interest to us
18:43planets too close to their stars stripped of atmosphere solar flares sterilizing the planet's surface
19:13the planet's beyond the habitable zone icy or frozen
19:43planet entirely covered with water is another possibility
20:13and what we're working on is better understanding that origin of life setting
20:24what is the chemistry required what are the interactions that make the steps to get to complexity
20:30do you need a hundred fields can you do it in one what are the other so there's a whole field of
20:35investigation that's building about understanding darwin's warm little pond he foresaw this 145 years ago
20:44and we're now just finally catching up to his prescient insight and really starting to try and
20:50scientifically address that and that that is very exciting that's what excites me in the morning
20:55from darwin's warm little pond come bacteria then algae perhaps a world dominated by algae
21:14perhaps a world dominated by algae
21:25yes well if you uh a product of uh of science fiction is that we uh we all assume that uh that other planets should uh end up uh looking more like our own except maybe the grass is a different color and a different shape
21:30uh in practice uh in practice uh because we understand so little about how um how life got started here on the earth
21:43uh it's incredibly hard to understand whether that situation holds or not uh and it makes for you know fascinating literature
21:55uh and a great discussion to have down the pub but it's not science yet
22:11what if eukaryotes diversified differently than on earth branching only three or four times
22:19never seeding the world of animals plants becoming the dominant life form
22:23so what we expect to find on on other planets um in some ways we don't know that they'd be different
22:42in the in the broad view because uh organisms still have to be able to do the same things
22:49they have to be able to get energy they have to be able to get nutrients convert all those to useful
22:55products and they have to be able to reproduce so organisms are always going to have these characteristics
23:02and we are confident that in order for animals or any organisms to become more accessible there has to be
23:10some sort of natural selection so the way natural selection works is that you have variation amongst
23:17individuals there are many more individuals that are made that can survive in the environment
23:25those that are better able to do their job have more kids and we start moving along that trajectory of
23:35accumulating adaptations things that they're able to do better than others outside so these basic
23:43processes are going to be what drives the change in in life over time
23:59well there's a lot of basic physical conditions that are going to be common throughout
24:05planets and the life forms that evolve on them
24:07um and so being able to sense distance i guess is one of those things could you get better depth
24:14perception with more than two eyes it's hard for us to tell well so many animals have many more than
24:20two or three eyes and it depends really what you want your eyes for so there are lots of organisms that
24:26have very simple eyes say a jellyfish has light sensing organs that go all the way around its body
24:33and these are able to help it move towards or away from light but if you want to be able to actually
24:40form images more than just light sensing these are structures that have to be evolved and they take up
24:50more space presumably also take some degree of brain power to be able to process that image
24:56and make them useful so if you had only two eyes and they could basically see 180 degrees or more than
25:04that is that ever going to be are you ever going to need more than that but we always know that the
25:10further apart you put the eyes the better your depth of perception will be i guess one of the things that
25:17might be advantageous of having multiple eyes is you could have
25:22different eyes that do different things so there are some fish that spend most of the time
25:27underwater and so to make it so that eyes work well underwater you make your optics the lenses
25:36act well underwater but then if the fish wants to look above the water the optics are all different
25:42so they can involve separate eyes or separate parts of eyes that are designed for looking through air
25:47rather than through water so having multiple eyes that do different things would be an advantage
26:00how about mobility how many legs are best
26:09two legs is pretty unusual so two legs is is not an advantage for most of the situations because they're
26:15quite unstable and so it takes us more effort to be able to stand on two legs we're more unstable more
26:23likely to be knocked over if we run on two legs we're more likely to trip and fall than an animal with
26:30four legs where you can have additional points of contact with the ground and running fast is actually
26:38easier with four legs compared to two with a galloping gate rather than a than a running gate but when we
26:46look throughout the animal kingdom we have a lot of different diversity in the number of legs if we're
26:50talking terrestrial animals and we know that more primitive arthropods like millipedes and centipedes have
27:01dozens of legs on their body but arguably more successful groups like insects have said
27:09six is enough for me and so they have sort of set their body plan to say i only need six legs i can do
27:16a lot i can change those to do different jobs but with those six legs i can become the most diverse group
27:24of animals that we've ever known there are other variations on that you get spiders that have
27:30eight you have crab-like animals that have ten um so part of the decision of how many legs you have is
27:40how adaptable can you make any of those legs if you do have lots of sets of legs that's going to limit
27:47um some things that you can do if you're always going to have a long thin body with lots of similar
27:54legs you won't necessarily be able to make big strong claws for doing particular jobs you won't be
28:03able to change your back half of your body to fit all your your digestive organs or your reproductive
28:10organs which is what insects do they've taken all their legs off their abdomen then they have this large
28:16structure that it's not filled in with all the muscles and joints of legs they can now put a lot of
28:23their organs in those so in many ways getting rid of some legs is useful well we know that looking at
28:33animals now we're looking at a tiny fraction of the total diversity of life that has ever existed on
28:39earth so we have a very biased view in what we think is possible but looking back in the fossil record we
28:45can see that um animals that in some ways define description have existed we don't know exactly
28:52how they lived and we imagine that many of these were sort of evolutionary dead ends they tried something
29:00out it was successful for a while but something out competed them something ate them to extinction
29:06uh and extinction events themselves will have um taken portions of that diversity away
29:20if life were well established on a distant planet filling every possible niche would it suffer extinction
29:41events similar to those that happened here on earth is that in fact necessary for evolution to produce a
29:48technologically advanced intelligence
29:56probably the very earliest extinction event that was um that occurred on earth was what's called the
30:02great oxygenation event where basically the earth converted from what was almost entirely an anoxic
30:09environment so there was no oxygen available into something that's highly oxic like it is today so
30:15oxygen started to emerge in the atmosphere and it's thought that this process occurred because basically
30:22single-celled organisms called cyanobacteria first started to evolve but what these do is a process called
30:29oxygenic photosynthesis which is basically where they um fix carbon um using light and they generate
30:37oxygen as a byproduct from this so they basically perform a very similar function to what plants do
30:43the majority of the history of life has been single-celled organisms so we know that it was very
30:50difficult for organisms to get past that
31:01earth has endured five mass extinction events in her history it is a case for saying that we humans are
31:07the direct result of those events which were catastrophic for other species
31:18i think we would definitely expect that if the formation mechanisms of um planets on other stars
31:25around other stars are similar to the solar system um then yes you would expect that there would be impacts
31:31um on other planets in the same way that they've been uh in our here on earth one of the important
31:40things to remember is that not all of the extinction events that we've had here on earth are believed to
31:45to have been mediated by impacts some of them have been mediated by um global climate change
31:52the snowball earth events which are thought to have had more to do with where the continents
31:58and the plates are on the earth uh and therefore where the the snow and ice formed and how the
32:04feedback processes um changed for us from us having our current environment to a much more
32:11tropical environment much warmer planet which we've had in the past to much colder planets which we've
32:16also had in the past one thing we do know about about evolution is that you know there's a certain
32:22number of available habitats and when they get filled up life doesn't actually need to evolve very much
32:31because it fills those habitats so you know the dinosaurs and that community was around for 150 million
32:38years they were pretty successful they filled up essentially all the different niche space with
32:44the plants and everything else and stuff and the pterodactyls in the sky and it took a meteorite impact to
32:50break that effective filling of the niches after that time of around 66 million years ago when
32:58this major extinction event happened there has been phases of cooling of the earth and perhaps that would
33:05have greatly affected dinosaurs in different ways from the extinction event and that's one of the
33:13things that mammals have been able to diversify into is this change to a cooling earth that increased body
33:23size and and furredness has enabled them to to fill those roles and so these extinction events these
33:32impacts or giant volcanic events that you know change the atmosphere and stuff they're almost
33:37like wiping the site clean and you can start over again and and so then life adapts very quickly during
33:42those change periods and fills that niche space again but it does so in a different form and that's where
33:48these evolutionary steps are able to develop and at each step you could argue that there's increased complexity
33:56but you know one of the things we're finding out is that we're not alone in being intelligent
34:01right dolphins are very intelligent they're the top predator in their niche space there's this all this
34:07incredibly complex interactions between predator prey and you know building up chemical arsenals it's
34:14just incredible what happens on a daily basis and so you could argue that development of intelligence
34:23is an inevitable consequence of increasing complexity and development through time whether it's in the
34:29form of a human or a porpoise or a dragonfly or something you know once they have to figure out ways
34:35to solve problems to be competitive and develop the right tools then there's that possibility of
34:41developing great complexity because you and i and really all life on earth is just a matter of
34:47organizational principles it's really just complexity right so we're able somehow to stand on two legs
34:54whereas most walk around on four but that's an adaptation to environment with this changed knee
35:01space so you could argue that if you let that experiment run again and again and for longer and longer
35:07that you would probably end up with something that has intellectual capability in terms of problem solving
35:13and we know that now you know we know many animals even spiders use tools so you know we're finding
35:19we're less and less unique but the level of complexity and adaptability is certainly you know at a very high
35:27level in in humans and time is a great friend you know time gives you that ability to complexify
35:35um but the extinctions yeah maybe they were a really critical marker in terms of allowing this form of
35:43complexity to develop other considerations when it comes to exoplanet environments have to include
35:54differing gravity atmospheric density and planetary spin around the star within a reasonable degree i'm of
36:03changing gravity i don't think that would have a big difference only with a massive change in gravity
36:09would i think things were different but if say you decrease the gravity a lot that would make flight
36:15easier so maybe you'd find many more animals that are flying or gliding than we do on earth if you made
36:23gravity stronger you'd probably decrease the frequency of flight because it takes more energy to be able to
36:32overcome that force of gravity
36:38what about size would differing gravity create larger creatures depends in part if you live in the air
36:47or underwater because when you live underwater you are supported a lot a lot more so the largest animals
36:54that we've ever known live in the sea they're the blue whales and so their skeleton and their limbs don't have
37:00to be able to hold their entire mass for living on land there's some that suspect that the maximum size of
37:15vertebrates that we've seen which include the dinosaurs and some mammals are still relatively big
37:24according to that we think that their body size was not limited by the mechanics it was by getting being
37:31able to get enough food to feed a very large animal so being able to find a high enough energy food source
37:40and being able to move over the environment to get that seems to have been one of the major factors that
37:46limited their maximum size so we think that they could probably get bigger but they'd have to be
37:53able to feed themselves and have a big enough population to sustain themselves over a long time
38:04if you have a very fast spinning planet where you're changing from night to day
38:08very frequently um you would get less specialization in animals that do stuff at night and animals that
38:15do stuff during the day i would expect they would just be adapted to exist throughout that whole night
38:22day night day cycle and then you go the opposite way where you have a planet like mercury where the same
38:29face always faces the sun um it's possible that it's way too hot on the side that
38:35faces the sun and way too cold on the other and we might imagine that there's some sort of um lovely
38:42habitable zone but in that small gap between them where all life happens um and they then only have a
38:52single night day combination um for the whole of their life in 1961 astronomer and astrophysicist frank
39:02drake came up with an equation to determine the number of intelligent extraterrestrial civilizations
39:08that might exist in the milky way at any one time several factors of the equation are highly
39:14conjectural leaving a great deal of uncertainty about the answer so the drake equation essentially
39:22combines together a bunch of different uncertainties it breaks the problem of do we think that there's
39:28intelligent life out there in the universe that could talk to us down into a series of terms so
39:34there's a term for the rate at which stars form in our galaxy which we actually know reasonably well
39:40then there's a term for uh the rate at which stars have habitable planets orbiting around them which
39:48we're starting to get a handle on it's probably you know somewhere between one and a hundred percent of
39:56stars um and then there's a term for uh the time it takes uh life to evolve which frankly we've got
40:05almost no idea about what the mean time is for that happen we think on our on earth it took somewhere
40:13between 100 and 500 million years for for life to to first get started and then there's the rate at which
40:23intelligent life forms and we have absolutely no idea we have absolutely no idea how you go from
40:30the time scale to go from bacterial life or pre-bacterial life to multi-cellular life to eukaryotes which
40:38are multiple cells all living together uh then you get to multi-cellular organisms and then so we don't
40:45know how long or how common that is and then there's the whole how long does intelligent life
40:50uh last and we have no idea about that so there's a few terms in the drake equation that we know the
40:58rest of them have um are essentially completely unknown and when you multiply together a whole bunch
41:05of completely unknowns you've got still completely unknown so we really don't know um it's a handy way
41:12to think about how difficult the problem is uh and it reinforces that the problem is incredibly
41:19difficult to understand yeah that's the um that's the the million dollar question isn't it i think
41:27there's two components to that probably so the drake equation has nine components to the equation i think
41:33something like that and each one of those has a lot of unknown variables so you know if you say you're off
41:40by a factor of a hundred and one of those variables and maybe one of the variables is actually you know
41:46how many stars are in the universe we might be off by factors of billions if you have nine variables and
41:51you add those all off that's a big numbers game the other thing is that we occupy a very particular time
41:59slice and so you know if you think of our capacity to generate a radio signal that can be beamed across the
42:08universe that's an infinitesimally small sliver of time right we've had an advanced society since
42:16200 years or something or whatever and it's nothing the universe is 13.7 billion years old right so
42:24what's the chance of being at the right place at the right time to intercept a signal that sweeps by
42:29200 years right 200 years right so it's just a numbers game
42:49so
42:57beyond our solar system the next location for habitation is our nearest stellar neighbor
43:09proxima centauri here several planets have been detected some in the so-called habitable zone around
43:16their star sending a probe to the nearest exoplanet is a daunting challenge but not impossible even with
43:24today's technology
43:29so even getting a probe accelerated up to a tenth the speed of light would be extraordinarily
43:36technically challenging and that would then take 40 years to get to proxima sen
43:43the difficulty being that it would have to be extremely small to get it accelerated up to that
43:48velocity and so it's not entirely clear that it would have a big instrument package on it the other
43:55problem is that it wouldn't actually contain probably an engine that would enable it to slow down so it
44:01would essentially fly through the proxima sen system at the tenth the speed of light and so
44:09it would essentially take a bunch of pictures very quickly and try to send some information back and then
44:15you'd have to wait another four years for that information to get back
44:20look i think it's it's an interesting idea uh whether it's a cost effective use of uh of our time
44:29i'm i'm not entirely sure i think probably rather than trying to work out how to
44:33make a very small probe accelerate it up to that velocity and then fling it at proxima sen would be
44:40developing the techniques for building space-based the very complex space-based telescopes that would
44:46enable you to block out the light from proxima sen and try to actually image uh the planet itself to do
44:54direct imaging unlike doppler wobble unlike transit searches where you only seeing the star and the
45:01effect the planet has try to actually see the planet itself then try to get spectra of that planet to
45:06understand better what's actually going on on its surface
45:20it appears with all the evidence at hand the sum of the drake equation would currently be one plus
45:36we are the one the plus is the possibility of technological intelligence within our stellar
45:42neighborhood of a thousand stars the odds are not good it's not a question of the available environments
45:49of which there are many it's to do with the timing our time slice within the immense age of the
45:55universe may well leave us bereft of company for thousands of years before our emergence and after
46:02we are gone