Venus Could Have Supported Life For Billions Of Years. First Habitable Planet In The Solar System?

after decades of research including multiple Landers and orbiters science can definitively say Venus sucks seriously that place is the worst with its boiling temperature intense pressure sulfuric acid rain and more but was it always this bad according to new research from NASA and various universities in Sweden in the u.s. Venus might have actually been the first habitable world in the solar system and it might have maintained a reasonable climate for billions of years finally rolling over into a runaway greenhouse effect just a few hundred million years ago today venus is a different story although the planet is roughly the same size and mass as Earth it has a dramatically different environment the average global surface temperature is about 475 degrees Celsius hot enough as I'm sure you've heard to melt lead the atmospheric pressure on the surface of Venus is 90 times the pressure of Earth want to experience the same kind of pressure dive down one kilometer under the ocean and you'll get an idea how do we know the Venera program the Soviet Union sent a fleet of spacecraft in the 70s and 80s to try and land on the surface of Venus 18 were sent 13 actually made it into the atmosphere and 10 survived all the way down to the surface able to send back some data to earth before they expired in the brutal environment but we're looking at Venus 4.5 billion years after its formation with the rest of the solar system and over those eons the Sun has been heating up venus has been getting dried out and many planetoids and asteroids have been smashing into each other but if we roll the clock back when could Venus have been habitable and for how long a new paper entitled was Venus the first habitable world of our solar system was released in August 2019 the temps to give us a glimpse into the van news in past it was written by dr. Michel way from NASA's Goddard Institute for Space Studies as well as researchers from Sweden New York Arizona and Maryland according to the study Venus probably started out with a similar overall composition to earth including the same amounts of water and gases in its atmosphere today of course it's bone-dry with a mere six quadrillion kilograms of water in its atmosphere now I know six quadrillion sounds like a lot and it is but Earth has more than 200,000 times as much water in its oceans atmosphere astronomers were able to calculate how much water it used to have based on the ratio between deuterium and hydrogen in its atmosphere and this indicates that it must have had much more in the ancient past even though Earth's atmosphere is 78% nitrogen Venus actually has double that amount and of course an insane amount of carbon dioxide planetary scientists have calculated that ancient Venus had shallow seas across its surface measuring from four to 525 meters deep the question is how much did it have and how quickly did it lose its water the traditionally accepted answer was that Venus lost its water quickly within the first hundred million years or so dr. Wayne his team used Goddard's Rock 3d simulator that I mentioned in the previous episode to simulate an ancient venus with shallow oceans and an earth-like atmosphere they worked with a few assumptions the first is the length of a day on Venus today the planet takes 116 days to turn on its axis you could walk faster than Venus turns not only that but the planet is rotating backward from the other worlds of the solar system it's possible that Venus was smashed by a massive planetoid early on in its history but it's also just possible that tidal interactions with the Sun slow down as rotation rate almost immediate and it's been rotating this slowly ever since they had to consider the surface of ancient Venus which is actually a total mystery and that's because the entire landscape was completely resurfaced just a few hundred million years ago as if the planet turned itself inside out and it's believed this happened because Venus doesn't have plate tectonics like Earth instead of regular volcanism releasing heat and pressure the planet resurfaced itself in a catastrophic event so they based their models on the current surface features of Venus as mapped out by NASA's Magellan spacecraft they filled the lowlands with water assuming an early ocean that was about 1/10 the volume of Earth's oceans and they assumed that early Venus had an atmosphere as thick as Earth but made almost entirely of nitrogen with trace amounts of carbon dioxide and methane like earth and then they just ran the clock forward watching how the planet changed over billions of years as the Sun heated up and Venus tried out what did they discover we'll get to that in a second but first I'd like to thank Roman Brendel Matthew Nichols vengeful sorrow Paul wheeler and the rest of our 825 patrons for their generous support educational content should be freely available to anyone in the world and the patrons make this possible join our community at patreon.com slash universe today and get in on the action the team performed five simulations based on different amounts of water coverage three of the scenarios assumed a deep ocean with an average of 310 meters one scenario used the Earth's topography and a 310 meter deep average ocean they also tried a scenario where all of Venus was covered by water 158 metres deep they simulated the planet at 4.2 billion years ago 715 million years ago and today watching as the amount of radiation coming from the Sun increased over time today Venus receives twice as much solar radiation per square meter as Earth does in all five scenarios they found that Venus was able to maintain stable temperatures ranging from a maximum temperature of 50 Celsius to a minimum of 20 Celsius and it kept these stable temperatures for almost three billion years in the beginning the planet had an incredibly thick atmosphere of carbon dioxide but as it cooled down over the next three billion years this carbon would have been drawn out of the atmosphere and locked away into silicate rocks by 715 million years ago the planet would have had that one atmosphere of nitrogen and other trace gases in fact it could have remained stable with liquid water on its surface all the way until today but some dramatic event happened hundreds of millions of years ago that transformed the planet forever and it might have been linked to that volcanic resurfacing that I mentioned earlier in fact Earth had a similar situation about 250 million years ago when the largest volcanic eruption in our planets history covered an enormous amount of Siberia the eruptions carried on for two million years and led to one of the greatest mass extinctions in our planets history so that the worse and Venus never recovered with the extreme heat from the molten rock releasing all that absorbed carbon dioxide into the atmosphere and leading to a runaway greenhouse effect the simulations depend on the fact that Venus cooled down and was able to condense water onto its surface to form these global oceans and they assumed that this volcanic resurfacing happened just once recently and wasn't a regular occurrence on Venus it's incredible to think that Venus could have been habitable for billions of years and if it wasn't for that catastrophic resurfacing it might still be habitable today in order to get to the bottom of this mystery we need to return to Venus with new orbiters balloons to study its atmosphere than even Rovers and Landers made of tough new heat tolerant electronics to explore its surface unfortunately there are no missions at Venus anymore and none are planned in the near future so the mysterious history of Venus have to remain that way for a few more years what do you think do you think Venus should be a higher priority now let me know your thoughts in the comments here are the names of the patrons who support us at the $10 level and more want to see your name here and support the work we do go to patreon.com/scishow Universe Today once a week I gather up all my space news into a single email newsletter and send it out it's got pictures brief highlights about the story and links you can find out more go to Universe today.com such newsletter to sign up and did you know that all of my videos are also available in a handy audio podcast format so you can have the latest episodes as well special bonus material like interviews with me show up right on your audio device go to Universe Today to calm such audio or search for Universe Today on iTunes Spotify or wherever you get your podcasts I'll put a link in the show notes I talked about the plucky Soviet Venera program that was able to actually land on the surface of Venus it was an incredible series of missions that inflicted untold horrors on robotic spacecraft and if you want to learn all about it watch this video next

Channel: Fraser Cain

Views: 189,138

Rating: 4.8678117 out of 5

Keywords: universe today, fraser cain, space, astronomy, planet venus, habitability of venus, venus, earth, solar system, greenhouse effect, runaway greenhouse effect, plate tectonics, surface of venus, venera program, soviet union, nasa goddard, nasa magellan spacecraft, missions to venus, carbon dioxide, mass extinctions, volcanic eruptions

Id: sB4XzrEv9dU

Length: 10min 2sec (602 seconds)

Published: Tue Sep 24 2019