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