(Intro)

Blood Falls! Not only has one of the awesomest names of any location on Earth, I mean we were trying to come up with a good joke to tell, it turns out there's actually a Vampire Diaries fansite call blood falls. So it turns out we didn't even have to write a joke, it was already existing in real life. But Blood Falls, in addition to being a Vampire Diaries fansite, is also probably the southernmost of the weird places that you might visit in your lifetime. If you happen to ever visit Antarctica.

You've heard me go on before about Antarctica's sub-surface lakes. I go on about them because they're really nard-rockingly amazing, rivaled only by the deep ocean floor as the unlikeliest places on Earth where scientists keep finding strange new living things.

In early 2013, for instance, scientists reached the ancient underground Lake Whillans in West Antarctica and found microbes under 800 meters of ice, about 5,000 bacteria in every teaspoon of water, where temperatures can reach -5 degrees Celsius and no substance has ever known the case of sunlight.

At Blood Falls, it's even stranger, and cooler to watch.

Here in a valley in East Antarctica water periodically emerges from the sub-glacial lake 400 meters underground.  And the water is not only super salty, almost three times saltier than seawater, it's also incredibly old and it can run as red as a vampire's eyes.

The story of Blood Falls begins around 5 million years ago when East Antarctica was inundated by the sea, forming a salty lake.  Some 3 million years later, glaciers began to form and moved over it, isolating the lake and its inhabitants from the rest of the world in a biological time capsule.

As the salt water on top slowly froze, it made the remaining water underneath saltier and saltier, so much so that today, even though it's now well below zero degrees Celsius down there, the water won't freeze!  And in addition to being wicked cold and hecka salty, the water is also chock full of iron scraped up from the glacier by the bedrock below.

There's almost no free oxygen floating around under the ice, but when the iron-rich water reaches the surface, oxygen in the air turns the iron into rust, and not just a tawny brown rust but a rich, red, sanguine rust that gives the falls its name.

So it's a site to put on your bucket list for sure, but I gotta say the most amazing feature of Blood Falls is what's been found living there.

For 2 million years, in a salty liquid habitat that probably tastes like roofing nails with no light or breathable oxygen, a community of microbes has found a way to survive that scientists say has never been observed elsewhere, by using iron to breathe, kinda.

The bacteria actually seem to get their energy from sulfur, much like those found at deep sea thermal vents, which they're probably related to. At Blood Falls, they respire by breaking apart oxygen-containing sulfur compounds called sulfates, but then the leftovers of this reaction interact with the iron in the water to restore those sulfates, essentially recycling the organisms' sole energy source.

Pretty slick, right?

The fact that organisms can survive like this has all kinds of implications for understanding the capacity for life, not only on other worlds, but also in Earth's distant history.

Like during the so-called snowball Earth period when much of the planet was thought to have been covered in ice some 700 million ago.

So, Blood Falls.  The next time you visit Antarctica you should totally go there.

Thanks for watching this episode of SciShow.  If you have any questions, comments, or suggestions of other weird places we should talk about you can find us on Facebook, Twitter, and of course down in the comments below!  If you want to keep getting smarter with us here at SciShow you can go to youtube.com/scishow and subscribe.