Us for michaels last stop. Please. If we just take the time to observe it nature provides us with a fascinating spectacle. Over time the inhabitants of our planet of woven complex relationships of collaboration symbiosis dependence and predation. Earth the planet of life running crawling for flying life abounds everywhere. But for this beautiful diversity to have proliferated earth has had to provide a favorable environment for around 4000000000 years. More than with the conditions which enables the blooming of life on earth. And could these conditions be present elsewhere resulting in alternative ecosystems. In an attempt to answer these questions scientists get all the cosmos for signs of life. They built giant telescopes with which to probe the universe and listen to the whispering of the stars but space has remained resolutely silent. Scientists have sent probes to the very edges of our solar system. But all they have sent back has been images of planets inimical to life. Over the last 25 years however astronomers have discovered thousands of incredibly diverse planets in our galaxy alone. So many strange worlds with no sign of life not one of a planet similar to our own so could it be that earth really easy to make. In this Program Scientists will tell the fascinating story of how earth developed how this bowl of ice and dust became the planet of life. In their liberal and trees all around on the ground they continue their research into the extraordinary circumstances which allowed life to appear and eventually transform this planet. They said local columns although we were trying to understand with all the possible outcomes what it was that made the uniqueness of our system or system now chris it seems like earths climate fix that self to always be favorable to life thats amazing sickish are those who dont know. Each will explain the incredible saga from the viewpoint of their own discipline from the birth of our planet to todays ecosystems its a story punctuated by an incredible succession of lucky accidents of all if you like that usually theres the analogy with the lottery they get. You know if the probability of winning is that i need to win the game of planetary formation forming a solar system with our earth is like winning the lottery. Scientists are only now 15 together all the various chapters of these turbulent history our history that of a succession of helpful not just lucky chances and beneficial cataclysms. Without a helping hand from jupiter and saturn and without the moon without hurtling comments without the power of volcanoes without the genius of certain microorganisms we would not be here if its possible that life is a one off if were successful you know or else that only our last has all the conditions necessary for life as we know it theyre going to quit the. Next day also sausage in that sense earth is probably unique although we may detect some life elsewhere that it will necessarily be completely different. Only it was this mind blowing series of improbable events that made the earth the possibly unique life bearing planet it now is. The idea that earth may indeed be meek could have been spawned by these famous photo taken on the apollo 8 mission in 1968. Changed our way of looking at earth there is al planet floating like an oasis in the magnificent emptiness of space. For the 1st time there we all were bacteria mammals insects and plants on the same photo our planet a unique ecosystem and even today this photo. Of a world with clouds and envelop in its. The an atmosphere could be a learn in the universe. The 1st reason earth was able to become this welcoming blues fear is because its at just the right distance from the sun in a narrow zone not too harsh and not too cold where the temperatures are compatible with liquid water and life. But planetology just have discovered that earths a very presence in this goldilocks zone is itself to to an amazing stroke of luck. When the solar system was still young the sun came close to being taken over by the planet jupiter so how was earth able to form here. Research into the onset of this puzzle has been carried out at nice observatory. Alessandro movie delhi has written a new account of the birth of our solar system. How many is a lot is it is the climate working on the origin of planetary systems as like being attacked if you arrive at the crime scene and use the clothes to try to work out what happens if a sea. Knew about the abuses them so that act will issue from our solar system as it is we try to reconstruct how it formed and develop doc when we come up with a scenario we get a shiver of excitement with thinking that maybe weve got close to what actually happened to us here or. Planetology just start from the present position of the planets attempting to hypothesize a scenario of the Solar Systems formation with the help of computer simulations. Our solar system like all planetary systems formed from a cloud of gas and dust that surrounded the young son 4500000000 years ago. But now solicits dim seems to have a very different structure from the majority of planetary systems discovered over the last few years. Is all agree we now think that our solar system is pretty magic with them so they have a lot of chance events had to happen to fred to be as it is usually this suggests that our solar system isnt a typical planetary system but a relatively rare one more. Because shamash when we look at planets around other stars we see that when its of a similar master jupiter are found an earth spark class then i feel this is important if jupiter was in this part of earth it wouldnt be here so they pull up. The discovery outside our solar system of giant planets similar to jupiter but much closer to this star posed a serious puzzle for astronomers because giant planets of that kind cannot form in such zones really planets are far with lana to form in a disk of gas and dust that surrounds the young star the giant planets form far out where its cold where theres ice which lets these planets grow to a huge size close. Like a snowball rolling down a snowy heal the planet grows ever. Or bigger as it gathers to itself all the dust in its path. It calling it collect when a planet gets big enough when it acquires enough mass it migrates inwards towards the star was on the. Understanding this phenomenon was a real revolution planetary migration explains why the majority of giant planets discovered elsewhere in the galaxy dont stay in their distant orbits as they formed a spiral inwards towards this stone but in that case why didnt our own giant jupiter migrate closer to the sun why did it stop just in time leaving the space free for the future earth. Young scepter should on football saturn is very important this is a giant planet too and as weve studied the dynamic between jupiter and saturn weve realized that saturn was able to stop jupiters migration and even reverse that conviction so jupiter started migrating to the sun but when saturn appeared there was a complicated gravitational effect which reversed the migration and the planets moved further from the sun one usually. Thanks to saturn the giant planet jupiter changed trajectory it left the in a zone of the solar system and it was this change of course that saved earths future. Without the intervention of saturn and jupiter would have ended up in the zone where earth now is earth would never have formed. Our planet was luckier than its future neighbor. Because on its migration jupiter passed through design when mars was forming. The giant planets swallowed up a lot of the material available leaving only crumbs for months and now neighbor would end up with 110th the mass of earth which in turn reduced its possibility of maintaining an atmosphere favorable to life. Could i make us were understanding how planetary migration totally changes how the planets get distributed player size their position in space and the collisions between these objects before they stabilize the planets make the system developed and its only particular way with a 50 year. Narrowly saved by assassin our planet could keep on growing and being just the right distance from the sun meant that it would later have liquid water on its surface. And yes 4500000000 years ago our planet was completely dry it formed in the rockies own of the solar system gathering up dust with barely any water content so where did this water which would later give us our oceans come from. After initially in danger ing our young earth jupiter would give it a helping hand. For most young to be deadlocked cos we think that the formation of the growth and the migration of jupiter let these bodies which formed far out in the Solar Systems and so there was cold bodies with water they sent towards the enters i dont know where they crashed into the still forming earth contributing their elements to it up or down or zillion more that they. These bodies asteroids and comets enrich the chaotic pull of mass which both thin walls with water but as our planet started to solidify the water molecules remain trapped under the surface in the magma. Yes an essential mechanism for our planets future was already in place and starting to bring some of that truck to the surface. Its a mechanism thats still very active today. With. These folks hey knows these mountains of fire has been helping to bring water to the surface from the very beginning in earths youth there was a lot more full kind of activity than today. So michael i mean how both when you 1st think about it you think of lava danger and life threatening option but volcanoes are essential for life as we view it that can occur in the. Sailor destruction on duty does the struction a San Juan Village by them ok no particular team in 1940 on too bad the people had to move away it was a real catastrophe so to know the artist has made the volcano quite small to get the whole region was devastated. Yes it appears from nowhere in a cornfield was i thought no one could have expected it when the village was destroyed that it was still quite small but take all. You would call some balck a nose arent inimical to life on the contrary they were necessary for life to develop throughout earths existence to do cool things things about them. But also are such explosions common. They happen but just not that office ive been here 6 years and ive seen 4 or 5 with an explosion like that of ash may fall on surrounding villages forest and you guessed it so whats the gas made of to complete it. Ill say its 95 percent water vapor in all ok no the around the world its mostly water was on a preserve all along. The water vapor spat out by the volcanoes allowed the water trapped in the earths ballast to make its way to the surface. This has always been an essential mechanism for keeping our planet hydrated and alive. Point 4000000000 years ago thanks to the volcanoes earth sky changed filling with clouds. Dilute the and rain started to lash the surface ukraine for millions of years and the 1st oceans formed. Yet barely had they appeared than they could have just as quickly evaporated. As to finish seems the difficult bit is having liquid water you dont just need age to well you need enough atmospheric pressure at most an atmosphere on the moon theres no atmosphere so theres never a better you look at what you want to. Give birth cert must be a hadnt been dense enough the water would have evaporated into space in the form of vapor. Fortunately the gas produced in abundance by the volcano has maintained enough of an atmospheric pressure for earth to be able to hold on to its early oceans. But the oceans of the young earth soon faced another danger that the freezing over. The sun was still weak 30 percent less bright than it is now earth therefore needed a greenhouse effect to keep its surface warm enough and its water in a liquid state. This greenhouse effect appeared very early on in earths history thanks to the water vapor and c o 2. Abundantly present in the atmosphere. Will be in the city today of course we know that c o 2 increased by human activity is a bad thing too much as a good but we needed some back then and still do if there wasnt a bit in the atmosphere the surface temperature would be 15 degrees colder can in fact then with the sun younger and less bright it would have been much colder cougar earth would have been frozen but about minus 60 degrees thats also not favorable to life he said of. The volcanoes where yet again contributing to making earth habitable in their ex aleisha as they were constantly spewing out huge quantities of c o 2 along with the water vapor. The c o 2 sat out by the volcanoes accumulated the greenhouse effect increased the ice melted and the oceans thought it could be we think this happened 400 to 500000000 years ago we call this period snowball earth and earth emerged from it like that if its the greenhouse effect increased and we got back a climate with liquid water favorable to like. Be celibate. But with the constant eruptions the c o 2 from the volcanoes was steadily accumulating in the young earths atmosphere the greenhouse effect could have gone out of control turning out planet into a furnace. Fortunately that was a safety valve c o 2 can dissolve in water. Over millions of years and its trapped in calc areas formations and no longer acts as a Greenhouse Gas he remains trapped you know at the bottom of the ocean in mineral form. The quantity of c o 2 in the atmosphere then very stupid being on the amount of liquid. Water on the surface. Of a very long time scales this make an ism regulates our planets climate. Fascinating thing about or which may make it unique is that all through its very long existence all 4 and a half 1000000000 years variations in the luminosity of the sun have been compensated for by a variable greenhouse effect. And if its. Like a sort of geographical thermostat keeping the earth always in a habitable with oceans on the surface want to show us. That these thermostat needed one more tweak to get it working perfectly and make our planet truly favorable to life. Over hundreds of millions of years the c o 2 in the atmosphere could have ended up trapped in the form of count carious wrong at the bottom of the ocean. It wouldnt have been enough in circulation to keep the thermostat going and it would have broken down. A mechanism possibly unique to our planet allowed for the reinjection of c o 2 into the atmosphere plate tectonics. That their life was compunction you have to realize that the earth has a sort of crust of cold and solid rock inside theres a warmer rock the mantle which changes shape and all this is. A clue so you might imagine that the crust forms a solid complete shell like an egg shell around a softer inside but thats not right the movements of the shifting rock on the inside were powerful. Enough to rub up against of the crust and a crack in the places that. The earths crust is fragmented into 10 plates which are displaced by the movements of the mantle. Where the plates come together they crunch over each other dragging the rocks that were at the bottom of the ocean deep into the bowels of the earth and also just the c o 2 recycling begin. Under the enormous pressure and heat the ropes melts and the magma is spewed back out onto the surface taking the c o 2 with it. The c o 2 escape seen gas form during volcanic eruptions finally back in the atmosphere the c o 2 may or may not be captured again by the oceans depending on climatic conditions the circle is complete. Sent on most issues its a very particular geophysical thermostat which we think has really controlled the climate conditions on earth and made a life impossible namely that just. To see if you changed in the plate tectonics just a little having slightly more or fewer than 10 plates and then with the recycling in c o 2 concentration would have been different and the bias heres what evolved differently or to. See. If there yes so and this begs another important question of gold sick this at plate tectonics just which seems to be the key the key to life on earth there is in light tectonics something really common in the rest of the galaxy angels and or something unique more very. Prayerfully ha and thats all our system you dont find anywhere else in the back and i knew by your. Plate tectonics may be the factor which earths neighboring planets lacked for life to appear and survive then. Yet one of the Solar Systems on the rocky planets did get off to a good start early in its history with volcanoes c o 2 and mars enjoyed an environment similar to earths. I dont know if you so there was an environmentally im not imagine a blue mars with lakes and rivers up on something there was an ocean in the Northern Hemisphere it also it was an environment of favorable to life of peace and i think. All would seem to have been set up then for the planet to function in a similar fashion the current state of the red planet however clearly shows that something went wrong. So mass and young mars cooled down much faster and i disagree massive plans mars is half the size of earth and its a bit like comparing a huge pot of hot water to a cup of d. C. I mean bushels of a big part cools lower than a cup of tea which is mars i dont die and that the inside call it faster is south but they are so there was no chance as we understand it for plate tectonics to arise by you so if there was no recycling that could maintain a climate favorable to oceans for billions of years mars had hundreds of millions of years and there is something in there after at least came a very sterile planet and it pristine. Mars is tragedy is that its too small and fell into a deadly spiral because of its smaller mass there was insufficient gravity to hold on to its atmosphere and the drop in atmospheric pressure was the next or. And the solar wind swept it all away some of the water evaporated the rest froze blue monster became red mas a victim of its own small size. And i was about all out there so you think the earth is just the right size so why is there no flame tectonics on venus which is the same size as earth with us why is that time one of the unlike earth has been is has hardly any water the waters all gone and the mantle is very dry not very lubricated if you cant move much more doesnt place any plates on the surface especially new so venus has a sort of unbroken shell all around the planet it doesnt have the mechanism that earths atmosphere so its not just important to be the right size but to have water in the mantle of the devil they really dont want to. Birth has enough water to lubricate its plate tectonics venus doesnt and yet the 2 planets were formed from the same materials. One very special event during earths youth could have hydrated its depths. This is us you know this is the idea for the mantle to have got sufficiently hydrated sufficiently lubricated early in its existence earth suffered a huge cataclysmic hes in we think that the young earth was struck by another planet the size of mars which we call taya. A few tens of millions of years after its good earth suffered a cataclysm which almost destroyed just how bright the chaos of the Solar Systems origins. Still reigned. Measure you know imagine a round earth hundreds of moons or dozens of the planet mars colliding repeatedly these objects grow in the form planet maybe planets. If you suddenly an object the size of mars comes towards our earth and crashes into the surface at a speed of Something Like 15 kilometers per 2nd act and then the plume at possible. Thing crashed into earth the energy released by this enormous collision was equivalent to hundreds of billions of hydrogen bombs. Back to the impact is so violent that the impacting object is destroyed less still from the surface of the earth is completely liquefied and the core of the impacting body penetrates the earths mantle becoming part of the earths core we think the earths core fused with that of the impacting body. Back though. The collision was so violent that the water contained in the year was driven deep into with school mixing with the water already present there in this way they are hydrated the depths of the earths mantle making it possible later for the plate tectonics system to function. As. A speculative us but if its right and its impressive it shows us that for life to have existed on earth all this time that we needed that chance impact a very early in earths history to hydrate the mantle maintain its lubrication and have this phenomenon this geophysical thermostat all throughout the planets existence would have been. The seeming catastrophe would end up being beneficial in another way as earth gained a new companion which would play a major role in the blossoming of our ecosystem. Out of the cloud of debris resulting from the collision a new body would gradually form the moon. This is them down the earth moon system is unique in the solar system and as far as we know in the galaxy system its a very particular system where both objects are large objects this is why certain astronomers talk of a double planet but i had to go. Barely had it come into existence than the moon was already exerting a powerful influence over the earth because of its considerable size. The history of the earth moon relationship has been studied very closely thanks to the Apollo Missions. Ministry are pulled in the Apollo Missions placed reflectors on the moon surface now these reflectors are used today to reflect back laser beam as emitted from earth or that they are such as this one behind me i while. Theres a regular emission from here the color im glad so in the frat house soon did i phones. Today many observe the trees around the world like this one in the outdoor proponents monitor the moon closely every night Scientists Use a laser beam to make a precise measurement of its distance from the earth. So this balance and close up of these are important experiments because we can measure how long it takes the laser beam to go to the moon and. Back in so we can measure in real time the distance to the moon. And one major finding which we sort of knew before but are now sure of is that the moon is moving away its moving away at a speed of 3 or 4 centimeters per year. These measurements have shown that when it formed the moon was much closer to the earth than it is today. That is soon after the moon formed if anyone had been here to see the moon it would have been gigantic in the sky because it was so close to them said it was going to its 380000 kilometers from earth but 4000000000 years ago we think it was only 15000 kilometers distant doesnt make you mad that. That person who did it rocks so many of the moon had a 1st consequence of creating bigger tide and therefore maybe stimulating biological evolution in. d the times caused by the moon churned up the oceans and contributed to the dynamism of our ecosystem and the mutual attraction between the 2 bodies also had a crucial effect on the rotational axis. At the face of something modern that the effect wasnt just the times it was much more that it stabilizes the famous tilts on the angle of 23. 00 degrees i would urge to look at the silt in relation to its trajectory around the sun will be so they and this angle has a constant for billions of years then they see any bony nuno daughter that if the moon hadnt been there the earths rotational axis would have oscillated causing rapid changes in the climate and this could have had huge consequences on evolution that with rapidly alternating periods of glaciation and warming for example the less assume that the actual fuck. The moon helps the earth maintain a climate stable enough for the slow and gradual evolution of life. Without the moon the earth would have been faced with the same up he evils as its neighbor among us. Sure the mounds of mars phobos and deimos are so small that they play no stabilizing role on the rotational axis. Yet with there have been very big variations in the rotational axis of mars laughs. Whats more this rotational axis has moved all around the surface of mars yes the other stuff is office. Months became a desert earth a garden of eden. Live like the present earth moon system is the result of a long series of accidents making the earth and moon a unique couple in each. Earth now had a stable climate and atmosphere and liquid water and surely everything was perfectly set up for life to appear and evolve but the earth still lacks the basic ingredients of life organic molecules. All living things on earth a made of the same Building Blocks long carbon based molecules scientists now think that a large proportion of these molecules came from outside the planet earth. Limit if you are on any the organic molecule is the basic elements necessary for life as are found in space only to hold on to your destiny only when there are media rights some are 60 percent organic material which is you know and a lot else worth. The original organic molecules which may have some in the seeds of life on earth were present in the distant cold zone of the solar system but how did these Building Blocks of life travel to our planet the Rosetta Mission the 1st to ever attempt landing a module on the comet shed some light on this mystery. Jumpier be bring was one of the scientists behind the so Dangerous Mission so sisko on that was very good this is what we saw on the 14th of july 24th scene of when we got this we thought i suppose we cant land on that its not feasible with us if this is tiny it could you know thats not the whole thing is only 4 kilometers and its revolving around an hour after that i said we thought wed never find a spot to send down and it was crazy so it covered more for. A few months later the probe feeling managed despite all the difficulties to touch down on the comet cheery. Always he was a kid if you know here you see he lies leg and an object made just a few years ago and here the oldest object in the solar system said the same as when it was born 4600000 years ago it was the 1st time and it will happen again soon on that we set something down in the common. With the 1st in. Alice sees the scientists realize that comets are very different from what they had supposed you have value to go ashore theres no water on this comet surface you know there isnt an ounce of ice we thought it was and the ice with a few molecules not at all all we see here is organic material for that matter are getting. Thanks to the Rosetta Mission scientists discovered that comets are abundant in the Building Blocks of life. Up until then they had thought that only asteroids little rocky bodies with us in doubt. Since the birth of the solar system comets and asteroids have gravitated in the colder regions where they capture and store these original organic molecules. Then these comets and asteroids veritable messengers of life transport these molecules into the inner zones of the solar system. As they pass close to a planet they disseminate these Building Blocks on to the surface providing it with the wherewithal for life. Scientists are keen to undertake Laboratory Analysis of organic molecules similar to those which fell into earths oceans this was the aim of the higher boozer to Mission Launched by the Japanese Space Agency to bring back to earth a few fragments of this original organic matter. The sample was collected in july 29 teams 300000000 kilometers from earth the mission was a success or a mall this is the moment when it touched down the hallways he would pick it to see the leg touching down there you know i thought its mind blowing or a while but then you see it take off again capacity degrade the principle for taking samples as for it not the later it is wrong it touches down the fires the bullet and leaves again with the debris that the guy. Takes a few seconds with us and it all happens very far from earth of course theyre still. Asleep i think its completely mind blowing we hope that in a sample of this carbonaceous material from which we think well life on earth you get. The probe is bringing back a 10th of a gram of these precious Building Blocks of life similar to those which landed on the planets of our solar system some 4000000000 years ago. From this material we want to find out what the initial ingredients were in the waters of Earth Primordial oceans and all that made possible the great chain of terrestrial biology your version. Comets and asteroids could be the missing links of a long chain the chain began with the simple molecules found in the early cloud dusts and culminated with the Building Blocks of life from which life on earth 1st sprang the chain leading to life. Than. Half. Past. Foodways guinns mediately after the harvest. Fresh fruits often end up in the garbage instead of the supermarket. That should change with an appeal in the liquid that increases the sofa life of food. Is this a way to avoid waste. 3000. 900 minutes on you. How does a virus spread. Why do we panic and when well all be. Just 3 of the topics covered and a weekly radio show is called spectrum if you would like and new information on the clone of virus or any other science topic you should really check out our podcast so you can get it wherever you get your podcast you can also find us at dot com slash science. The power of influencers and what they mean for democracy. Welcome to 60 online session of global. Influencers have an enormous reach. Now increasingly voicing their opinions about political issues theres a new dynamic is emerging. What does this mean for democracy. Joining our discussion starts 1230 t. C. This is d w news live from berlin the belo group saw physician leader in brussels pushing for sanctions against her own countrys leadership that is the setting as European UnionForeign Ministers gather to debate penalties on president Alexander Lukashenko and others masterminding the crackdown on peaceful protests in minsk. Also coming up the banks at the center of the illegal deals totaling some 2 trillion dollars a massive investigation finds Financial Institutions facilitated corruption and Money Laundering on behalf of criminals