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5.Deadliest Space Weather S01E01 - Venus

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Today's forecast calls for a high of 900 degrees. A steady rain of sulphuric acid. And an atmospheric pressure high enough to crush your bones. It sounds like hell on earth; but it's just another day on the planet Venus. Scientists warned, that the weather on Venus, is the sneak preview of the future on earth. Eventually the earth will experience a runaway greenhouse. It is just a matter of time. What would happen if earth had to face this fate tomorrow? We would be in deep trouble. We would be fried to a crisp and crushed beyond belief. Earth's, is just one kind of weather. On other planets, there are storms beyond imagination. Climates and conditions that we hope to never see on earth. But could they happen here? And if so, could we survive deadliest space weather? Imagine waking up one morning to a very different earth. Our weather has been replaced by some other hellish weather from Venus. It's not a pretty picture. In fact, as far as life is concerned, it's the end of the world. Our lakes and oceans boil and evaporate. Our cities collapse into blazing and furnace. Our monuments dissolve in a torrent of sulphuric acid. If the weather on Venus were to certainly descend on to the planet earth, it would...probably, it would be a bad day. Venus like weather on earth may seem unthinkable. But, in fact, most scientists believe that it's inevitable. So they are struggling to understand, how things on Venus went so disastrously wrong? It's king of sobering advanced look of about the weather. Over the really long term it's going to be on earth. To understand how the weather on earth could spiral into what scientists call a runaway green house effect. We need to understand how a runaway greenhouse already happened to Venus; a planet that started out, lot like earth. Venus is the second planet from the sun and it's sometimes called the earth's twin, because it's so much like earth. It's almost exactly the same size and it has a big cloudy atmosphere. Looking at it from space you might think it was just like earth. But when it comes to weather, the two planets, are literally, worlds apart. The major differences between Venus and earth are that, Venus has a much much thicker atmosphere. Temperatures are 900 degrees Fahrenheit. Hotter than a baker's oven. Hotter than the melting point of tin and lead. You might assume Venus is so hot, simply because it's closer to the sun. But in fact, if you took earth and moved it as close to the sun as Venus, Global temperatures would nearly rise by 20 to 30 degrees Fahrenheit. That would not be so hot that life wouldn't be a problem. What really makes the weather on Venus so much hotter than earth, is the thickness of its atmosphere. On earth, the air is a light gas. On Venus, it's a thick boiling soup. By far and the most significant fact about the weather on Venus is that the atmosphere is roughly 100 times denser, than on earth. And so that dictates every feature of the Venusian weather. The atmosphere is so thick that walking through it would be like walking through water. Trying to move against it would be incredibly difficult. You really couldn't move easily through the atmosphere of Venus. All those surface winds are calm on Venus. Even a light breeze could cause problems. The winds on the surface of Venus are quite slow they are moving at just a few miles per hour. But because there is 95 times as much atmosphere at the surface of Venus, The wind at a given wind speed has 95 times the amount of of ability to kind of pull you along. The whole atmosphere is moving kind of like a river. A 5 or 10 mile an hour wind would probably knock you over. As a tourist on Venus, you might feel a lot of pressure to see the sites. But you would also be under a different kind of pressure. The kind you wouldn't survive! The pressures on the surface of venus are about the same as going half mile down in the ocean. Divers can't go that deep, it's just lethal; it would crush the men; so it's the same on the surface of Venus. Take a car which weighs 1500 pounds and put it on every square inch of your skin. Within seconds, you will crushed like an egg shell. But on Venus, the pressure might not have a chance to kill you because the heat would cook you first. On earth, the highest temperature, ever recorded was on July 10th, 1913 in death valley. When the mercury hit 134 degrees. But that would be far colder, than the coldest day on Venus. If temperature on Venus is roughly 800- 900 degrees Fahrenheit, that's hotter than the oven cleaning temperature setting on your oven. Humans have been exploring mars for years with remarkable success. But the severe heat of Venus makes exploration, practically impossible. On Mars, we can land a rover down and drive around for 6 years. On Venus, you land that same rover down it would start to melt into a pile. Imagine the solder on the electronics just turning into liquid and flowing out. And, unlike earth, with its wide variety of climates; on Venus, there is nowhere to hide from this inferno. Because Venus's atmosphere is so thick, the conditions on the surface of Venus don't wary very much at all between the equator, the poles, the day side and the night side. Even when it's night on Venus the rocks are glowing ever so slightly from their own heat. You would see the surface glowing, dull red- orange glow from the rocks because it's so hot. So, what would happen if earth would assort to 900 degrees. As the thermometer rises towards the temperature of Venus, towns and cities around the world, begin to smolder. Ray Bradbury was right; paper really does start blowing up at Fahrenheit 451. Sky scrapers around the world turn into towering infernos. The outer rims of the building would be; what burns hottest. That's because it's most exposed to that 900 degree furnace from the outside. The outside of the building would probably pull away and begin to drop off. Steel begins to soften and lose strength at 600 degree Fahrenheit. As the world goes up in flames, everything from home to skyscrapers, burns and collapses. Despite the heat on Venus, it's actually a dim darkened world, shielded by clouds that block out the sun. But those clouds, hold a secret so deadly that even if you could survive the incredible heat and pressure of Venus, you would never survive this! Despite its hellish 900 degree temperatures and crushing pressures, the surface of Venus is surprisingly calm and clear. But once you rise up into the clouds, that uniform heat and pressure are replaced by wild extremes of heat and cold. And Venus's weather rivals the most violent storms on earth. The clouds at the top of the Venus's atmosphere are undergoing what's called super-rotation. There is zipping around the planet in just 4 or 5 earth days, moving at 200 miles an hour; and like strong hurricane winds here on earth. What's driving the circulation of Venus is this cold hot contrast. The sun is beating on the sun lit side and the other side is not having any sunlight. So that imbalance is ultimately driving the strong winds around the planet. As these winds reach the poles, they create one of the strangest weather conditions in the solar system. A cyclone with two eyes! And these super- rotating clouds of Venus have another nasty trait; that would make it pointless to carry an umbrella. The clouds on Venus are made of sulphuric acid. They are not very lovely clouds from our perspective. We wouldn't want to go flying in an airplane with the windows open through the clouds of Venus. Especially, when these clouds rain, they rain almost pure sulphuric acid. On earth we have coal plants that release materials that dissolve in rain water and it rains slightly acidic water. However on Venus, we have an acid rain beyond comprehension. It's so hot on Venus, that the acid rain evaporates before it hits the ground. But, what would happen if sulphuric acid ever rained down on the surface of the earth. A simple experiment... Mixing sulphuric acid with sugar, shows what it would do to the human body. I have some sulphuric acid here in this beaker. And I have an organic compound that has lots of carbon and oxygen and hydrogen, actually, just sugar from an ordinary kitchen. When I add the sulphuric acid, what's going to happen is actually going to pull the water out. Dehydrated. And produced a violent chemical reaction. So first I should put on some safety equipment. Make sure I don't get any of the fumes. So, adding the sulphuric acid to the sugar, which we are doing here. Would be the analogue of what would happen on Venus If some of the sulphuric acid in the atmosphere got in contact with some organic life. After being stirred it, I am going to get out of the way! The sulphuric acid turn the sugar into a killer of almost pure carbon. So, if it ever rains sulphuric acid on the surface of the earth, most life would be reduced to carbon pillars just like that. But what about our cities and monuments? Paris, France. If a corrosive downpour of sulphuric acid descended on the isle structure of the Eiffel tower. A... sulphuric acid hits iron. It turns the iron into iron sulphate. Iron sulphate is crumbly, grainy, it can crystallize, it's rather brittle, doesn't contribute to any strength at all. You will get a kind of a little bit of a green cloud around the Eiffel tower, because, you have so much acid coming so fast. And then you begin to see the first little signs of failure in the arches that hold the entire structure up. And you begin to see a slight deformation. And some of the rivets begin to fail. And as they fail, the structure itself begins to warp on its own weight. And then fall. Venus wasn't always a world of boiling heat, crushing pressure and sulphuric acid. There was a period when the weather was calm and water was plentiful. But then... Something began happening to Venus that holds a vital lesson for the survival of life on our own planet. Venus started out as a watery planet like earth. Until a climate catastrophe, stripped it bone dry. That catastrophe is key to understanding Venus's weather. And to understand that, you have to imagine this. One part of the story, may trace back to the giant impact from space that struck both earth and Venus, not long after they were formed. As the young earth was cooling, a mars sized planet struck a colossal blow. Earth emerged from this collision as a rapidly spinning planet with a massive liquid iron core. Perfect for generating a magnetic field. And that magnetic field protects earth's weather from dangerous charged particles from the sun. Without it, they would penetrate our atmosphere, and strip most of it away. A planet sized body, also struck Venus. But the result was very different. The impact slowed the spin of Venus so much, that it takes 224 earth days to make a single rotation. Some believe that the slow spin is the reason Venus doesn't have a magnetic field. A lack of magnetic field on Venus had an important part in making it a kind of a brutal place it is today. After this violent start, both planets cooled into very similar places. At least at first. About 4.5 billion years ago before the earth and Venus were formed, they were quite similar. Very similar in maths and shape. Venus would have looked a lot like Hawaii's Kilauea volcano does today. But unprotected by a magnetic field, its atmosphere was at the mercy of the sun's charged particles. They broke up the water vapour on Venus, separating the hydrogen from the oxygen. Then blowing hydrogen into space. Water molecules themselves were destroyed. The hydrogen was lost. The oxygen formed with carbon to make carbon dioxide. Since carbon dioxide is a potent green house gas, more carbon dioxide, meant even more heat. And finally, Venus crossed a critical threshold. Where it was too hot for the water to exist on the surface. What would happen if earth ever crossed that threshold? Chicago's lake Michigan. As the temperature sores towards the boiling point, the lake shore drive, is about to become high and dry. The water boils extremely fast at high temperatures. And once you get up around 600 degrees Fahrenheit, There is not much to keep the water from just going zoop (evaporate), and it's gone. You would end up with lake Michigan becoming a very large very thick cloud. Venus crossed that critical threshold perhaps over 3 billion years ago, in a runaway greenhouse effect. The temperature just kept rising all the way up, to 900 degrees. After that, The weather on Venus broiled for billions of years. But 600 million years ago, Venus suffered another global catastrophe. If it ever happened on earth, even the most tenacious life, couldn't weather that ultimate storm. Venus is the hottest planet in the solar system. One cause of it's hellish conditions can be found in a unique disaster, that changed its weather forever. A series of volcanic eruptions, so huge, they resurfaced the entire planet. We think that 600 million, may be a billion years ago, there was a massive release of volcanic energy from the surface. Magma, just being released from these cracks in Venus resurfacing the entire planet. How could this have happened? It all goes back to the lack of water. On earth, continents float on our liquid mantle. Creating rifts in volcanoes that release heat from the interior in an endless process called, plate tectonics. But, that requires water. On the earth, that whole process is lubricated by the liquid water that is both in the oceans and also is part of the rocks that form the earth's crust. On Venus, you don't have the hydration of the crust that allows plate tectonics to occur. And, so, every few hundred millions years, or so, you may get a huge sort of pools of melting lava which completely resurfaces the entire planetary surface. This catastrophe didn't just resurface the planet, it made the weather even more brutal. When you resurface an entire planet with lave, you're emitting enormous amounts of noxious gas into the atmosphere. That resurface would have given the planet the look and feel that it has today. Some say that Venus is a grim worst-case study of what could happen to earth, if today's global warming somehow led to a runaway green house effect. But, even if we could solve global warming, the sun is destined to heat up over hundreds of millions of years. As it does, the fate of Venus is likely to descend upon earth. Eventually, the earth will experience runaway green house. The sun gets brighter, as hydrogen burns to helium. Eventually, we will all go the way of Venus. But, that's a long time away. Our calculations suggests that it's 100 to 500 million years from now. So, the weather on Venus is really an advanced look of what's going to be happening on the earth. For the very distant future of life on earth, we're going to face all the challenges that Venus currently faces. It's lucky that we don't have to face those conditions today. If we did, our lakes and oceans will boil away, our buildings would melt, our monuments would crumble. But, the fact that a runaway greenhouse effect is even theoretically possible on our planet. It means that the weather of Venus holds vital lessons for the people of earth.

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Duration: 21 minutes and 14 seconds
Language: English
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Posted by: pgtranscribes on Apr 10, 2015

5.Deadliest Space Weather S01E01 - Venus

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