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  • Do me a favour right now

  • and picture in your mind the toughest animal on earth

  • whatever you think it is

  • and now imagine what that animal would do in the most inhospitable environment that you can imagine

  • so for example if you thought of a grizzly bear on top of Mount Everest

  • being attacked by a swarm of silverback gorillas

  • you would be wrong

  • that is neither the toughest animal, nor is it the most inhospitable environment

  • but I thank you for the visual image, that was a good one

  • do you wanna what he toughest animal on earth is?

  • well voilà, there you have it

  • my friends, it is the Tardigrade

  • also called a water bear or a moss piglet

  • because they're plump and waddly and they like to suck on moss

  • and you may have noticed they're actually kinda cute

  • they're what scientists call "Extremophiles"

  • which means they don't give a crap about where they live

  • the Tardigrades secret is that, when the environment gets to tough

  • they just shrivel up and die for a while

  • with the option of reviving when conditions improve

  • and that is the weird thing about Tardigrades, they're so extravagantly tough

  • like for no real reason, they're just supposed to like waddle around on moss and suck up water

  • that's their job

  • and yet in their dormant state, they can withstand temperatures close to absolute zero

  • and up to 300°F

  • they can survive being exposed to 1000 times the radiation that would kill an elephant

  • they can withstand pressures up to 6 times what you find in the deepest oceans on earth

  • what, what is the point of that, there's no ways that that would be useful on earth

  • and you had better believe, that we've been sending these little waddlers into outer space

  • because what is the most inhospitable environment? yes, it's space

  • in fact, scientists think that Tardigrades may be the key to understanding how life began on earth

  • back in 2007, NASA put a bunch of Tardigrades on the Space Shuttle

  • then they opened up an air locked door and left them outside in the vacuum of space for 10 days

  • being exposed to crazy amounts of UV radiation

  • then they brought them back to earth and when they got there, the Tardigrades were like: What's up?

  • they were happy and healthy and some of them laid Tardigrade eggs

  • and had little Tardigrade babies, that were completely normal and we keep doing it

  • earlier this year on the very last mission of the Space Shuttle Endeavour we send some Tardigrades up

  • and the European Space Agency send some Tardigrades into space

  • as part of a mission called "Tardigrades in Space"

  • uhm, which isn't clever until you realize that they shortened it to "TARDIS"

  • so the question is: why do we keep shoving these adorable little beasts uhm into the vacuum of space

  • it doesn't seem like a very nice thing to do

  • well, one: because we want to understand how Tardigrades work, just scientificly

  • how they can possibly survive these intense, horrible, inhospitable environments

  • and two: because we're interested in proving the Panspermia hypothesis

  • that is right "Panspermia" a word I'm not going to make a joke about

  • so imagine for a moment a meteorite slamming into our planet

  • and this meteorite is so large, that it actually ejects pieces of the earth into outer space

  • now imagine on those pieces of earth that got ejected into outer space, there are Tardigrades

  • if that little organism could survive the vacuum of space long enough to then fall down onto another planet

  • it could seed that planet with life, if life can be transmitted in that way

  • then it becomes much more likely, that life is a very very common thing in our universe

  • Panspermia hypothesis has been around for a long time, but thanks to Tardigrades it's starting to look a lot more credible

  • so we can already thank these beasts for being a great proof of concept for us

  • bot of course they will never now, that we are so in their dept

  • they're just going to keep walking around on mars, sucking water off and occasionally visiting other planets

  • I'm Hank Green, that was today's SciShow dose, we hope you learned something

Do me a favour right now


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B1 中級

タシグラード。素敵な過激派 (Tardigrades: Adorable Extremophiles)

  • 36 1
    robert に公開 2021 年 01 月 14 日