Let's Go Back To Venus!

Short Wave
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Automatic TRANSCRIPT

Ra jeff. So in this episode. We are making the case for exploring venus. Where do you wanna start. Why not start with the history. Venus exploration august twenty six the mariners countdown begins so the very first spacecraft humans ever sent to another planet mariner to and they didn't go to mars. It went to venus the first planet. Humans ever landed a program on that was venus to vienna. That was the soviet union's venera seven That landed on venus's surface in nineteen seventy. Got it okay jeff. So why did planetary exploration start with venus like that well because venus's actually pretty good place to visit it's closer the mars and it looks in some ways a lot like earth similar size thicker atmosphere. Yeah but it's not exactly suitable for humans right venus. It's really hot. I know it's filled with poisonous gases that can kill you. That's true that's all true. Fact check through. Its atmosphere is filled with sulfuric acid and the atmosphere so thick at the surface. It's like being under kilometer of water. Also it's so hot that lead melts. So when the russian venera probes touchdown. Martha gilmore planetary scientist at wesleyan university. She told me they didn't last very long. Those were able to operate for at the best an hour and a half before suffering what we call a thermal death I mean yeah. I mean they did not have a happy end but before they died. They did snap a few grainy photos and what they sent back didn't look great either. This desolate inhospitable world. And nobody's really tried seriously to get any closer since those soviet missions. Yeah and i mean mars by contrast even though it's colder and the atmosphere is thin and it's farther away at least the rovers we send their don't melt. Yeah okay sir. All i can see why. Mars is a favorite destination over venus. Yeah yeah okay. There's an argument to be made but the orbiter said have gone to venus and studied it from above. They're starting to build up this really interesting picture at the planet for starters. Scientists think that venus has had a super interesting past. Gilmore told me that a few billion years ago venus actually had oceans. venus should have had a lot of water and new climate model suggests that water may have persisted for billions of years That's pretty cool. I didn't know venus. Had oceans yeah. Yeah and i mean what's equally. Who is the story of what happened to those oceans so just bear with me for a second Basically the theory is that venus earth had volcanoes that we're putting out tons of carbon dioxide into the atmosphere now the oceans were scrubbing the atmosphere of the carbon dioxide there literally sucking up the co two as it was released but they couldn't keep up so the co two levels kept rising and just like we see here on earth with global warming The temperature got hotter. The ocean started to evaporate the start to shrink. And if you don't have that ocean you lose that mechanism to pull the o two down into rock and so that co two Has no choice but to stay in the atmosphere so venus keeps getting hotter the disappear entirely the co two levels. Go through the roof. It's this runaway. Greenhouse effect that eventually completely dries the planet out and co two and noxious gases. Blanket the surface. And that's how you get from a nice warm ocean. Venus the past of what we see. Today yeah this is kind of scary to hear in a way jeff because it sounds like climate change on earth i mean. Are we on a road. That's headed towards a venus like future. No no the short answer is no and that's because although the processes are similar there are parallels between earth and venus and climate change. Could get serious. It won't get venus bad because basically the earth is farther from the sun. Gotcha okay so that's not exactly what our earth hasn't store jeff wise. It's still worth it to visit and study venus well. There's this really interesting question of life i mean. I think there's an argument to be made. The venus was more likely to have life on it. In the past the mars ever was venus had this warmer thicker atmosphere and it definitely had oceans. Gilmore thinks that you are some extraterrestrial visitor in your swinging by from some other part of the milky way mars venus and earth would have actually looked a lot alike back. Then you know. Three billion years ago you would have seen three terrestrial planets of which have oceans venus earth and mars and at least on one of those planets life had already evolved and you know has led

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