Five lifeforms that can survive in terrifying places
Digital Reporter
Sunday, October 2, 2016, 1:53 PM - The search for life on Mars took an odd turn this month, when scientists announced marsquakes might be able to release enough hydrogen to sustain small lifeforms.
Given Mars' harsh environment, any life that does exist there, whether at the surface or far beneath it, would have to be very hardy indeed.
We looked into it, and it turns out there are plenty of lifeforms on Earth that can survive extreme conditions that would kill almost anything else. Here are just five cases.
Water bears can survive in the vacuum of space
Depending on your tastes, you will find tardigrades, or water bears, either adorable or scary.
Despite their name, they’re nothing at all like Canada’s ursine forest dwellers. The “bear” monicker is a reference to the creatures’ plodding gait, from which we get its official name ‘tardigrade’, or slow-walker. And rather than towering over humans, they seldom get much larger than 1 mm in length.
But what they lack in stature, they make up in a dogged determination to shrug off anything man and nature have to throw at them. We’re not saying they’re indestructible, but of all of Earth’s multi-cellular organisms, they come pretty close.
Exhibit A: They are the only known animals to survive exposure to the vacuum of deep space. The European Space Agency bundled a few thousand of them onto a satellite in 2007 and launched them into orbit, exposing them to a hard vacuum for several days.
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The New Scientist reports while only a handful of those also exposed to solar radiation survived, 68 per cent of those that were shielded from the sun’s rays made it through just fine, reviving upon exposure to water and even producing viable offspring.
The key to their unbelievable hardiness is their ability to lose most of their water and still survive, existing in a dormant state at 0.01 per cent of their normal metabolic rate. Even before the space mission, scientists knew their dormant states made them very resistant to extreme conditions for prolonged periods of time.
The BBC says one experiment found a tardigrade that revived after 120 years in dried-out moss. That experiment has never been duplicated, but in 1995, some were revived after eight years of desiccation. In the 1920s, one experiment found they could survive 21 months at -200oC in liquid air, -253oC for 26 hours in liquid nitrogen, and -272oC for eight hours in liquid helium. The last, you’ll note, is just a hair above absolute zero, the coldest possible temperature known in modern physics.
With traits like that, it’s no wonder they’re one of Earth’s most successful species. Fossils of the creatures date back 500 million years, and The New York Times says though they prefer moss and watery environments, they’ve been found from mountains in the Himalayas to deep ocean trenches.
Turkmenistan's infamous 'Door to Hell' has life in it
Even if you know about the remarkable tardigrades and their Wolverine-like healing factor, you'd be forgiven for thinking nothing could possibly survive within the fiery depths of Turkmenistan's Doorway to Hell.
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The blazing pit isn’t even a naturally occurring feature. The official story is that a Soviet natural gas drill rig collapsed into the cavern below in 1971. Scientists ignited the gas in what has proven to be a vain hope that it would burn off eventually.
But there’s other versions of that story. Vice reports one tale about a farmer who hoped to burn off the gas by rolling a burning tire into the pit, as it had been poisoning his sheep. In an interview with National Geographic, explorer and occasional Weather Network collaborator George Kourounis said the collapse itself may have happened as early as the 1960s, and ignition as late as the 1980s, though with spotty records, it’s hard to know for sure.
Kourounis is the reason we are talking about this literal hell hole: In 2013, he became the first person to explore the cavern by being lowered into it in a special flame-retardant suit. Amid the smokeless flames of what he called a “colosseum of fire”, part of his mission was to take samples to see if any life could survive in the blazing hot, methane-rich pit.
Image: Tormod Sandtorv/Wikimedia Commons
Incredibly, Kourounis did find bacteria that were apparently quite happy down there. Though Kourounis said they were “sparse,” the fact they existed in the pit at all was a major breakthrough.
"Outside of our solar system, there are planets that do resemble the conditions inside this pit, and [knowing that] can help us expand the number of places where we can confidently start looking for life outside of our solar system," he told National Geographic.
South Africa's "devil worms" live in infernal conditions
If you’re looking for something a bit more substantial than mere bacteria, you’ll have to go deeper than the hellpit pictured above, to find the appropriately nicknamed “Devil worms.”
A species of nematode, essentially roundworms, they grow no longer than half a millimetre, and are complex organisms. But unlike any roundworms you ever heard of, these were found deep within the earth in South African mine shafts -- as deep as 3.6 km.
Roundworms are known to be hardy, with some species surviving in hot springs, and many able to live in a sort of suspended animation during times of hardship, like the tardigrades. But these little guys are something else, such that Princeton University geoscientist Tullis Onstott said it was like “finding a whale in Lake Ontario.”
Aside from the pressure, the deepest dwelling of the species found by researchers lived in 48oC temperatures, able to survive in oxygen levels of only 0.5 per cent. And according to the researchers who found them, they are thriving, and it seems they are indeed living on bacteria that already exist at that depth, rather than washing in from higher in the mines.
In fact, Onstott’s colleague says they have it easier than their less stygian counterparts.
“Life for these worms is like summer camp in comparison with worms living on the surface," Belgian scientist Gaetan Borgonie, the worms’ codiscoverer, told the BBC. "The deep subsurface is a more stable environment than the hourly changing environment on the surface."
It's also a good indicator of what we might find when seeking life on other planets. If it can live in space, in a fiery pit, or kilometres beneath the earth, odds are it's hanging on somewhere out there.
There are some freaky things living in the ocean depths
From the sunless depths of the earth, to the crushing darkness of the ocean, this is where things get really weird.
To start, take a good look at the fish swimming lazily in the footage below.
The ethereal creature, dubbed "ghostfish" by its discoverers, it's pretty and elegant, but aside from its lack of eyes and translucent skin, it otherwise doesn't look too out of the ordinary -- until you realize the footage was shot more than eight kilometres below the ocean surface.
At that depth, the new species is officially the deepest-dwelling fish ever discovered. It was found by a special lander sent down by the exploration ship Falkor on its expedition to the Mariana Trench in 2014.
The ghostfish wasn't even sighted at the trench's deepest point, some 11 km down. Known as Challenger Deep, it's been visited by humans in the past, as well as drones, so we know it's far from lifeless. Here's what one 2011 expedition saw:
If you look carefully, you can see a jellyfish slowly passing by. The expedition also sighted sea cucumbers, as well as amphipods, similar to shrimp.
What was uncommon about those was how large they were, given the terrifying pressures at the deepest point in the ocean. Scientific American says some of those sighted were about 30 cm long.
You don't need to go that deep to find ones that big. An expedition to Kermadec Trench, north of New Zealand, found ones about that large a mere seven kilometres beneath the surface.
Image: University of Aberdeen
They're harmless (and even if they weren't, when was the last time you took a jaunt seven kilometres underwater?), but it goes to show that, despite the literally abysmal conditions of the deep ocean, something is bound to survive.
The bacteria that are older than the dinosaurs
Though to the human eye, the ocean floor may seem lifeless, it’s actually teeming with life. Popular Science says around 90 per cent of Earth’s microbes dwell beneath the ocean soil, and some of them really, really seem to want to live forever.
In 2009, a group of Danish and German scientists went to the North Pacific Gyre, an area of the ocean that is relatively nutrient poor, and started drilling ocean sediment to see what they would find. And when they looked at cores taken about 30 metres beneath the ocean floor, they found microbes that had survived -- barely -- despite a near total lack of nutrients.
Image: Wikimedia Commons
For how long? The researchers say they’ve been living their long and miserable lives for 86 million years. The dinosaurs were still merrily ruling the land when these microbes began descending into the mud, and Popular Science says they’ve not had access to a fresh food supply since then.
"They left the surface 86 million years ago with one lunch box, and they're still eating out of it," Hans Røy of Aarhus University told NPR. "It's like they're splitting a pie, and they keep splitting in half and in half and in half, but nobody ever eats the last crumble. It's quite remarkable."
They seem to be surviving by metabolizing what little nourishment they have very, very slowly, such that it would take them a thousand years to double their mass and, presumably, split (an E. coli bacterium does that in less than half an hour). Nevertheless, the researchers say they might yet outlive human civilization.
"These organisms have no clue that we're even around," Roy told NPR. "They could be sitting down there for 100 million years, and the whole surface could be one scorched desert, and they still wouldn't know it."
SOURCES: New Scientist | New York Times | BBC | Princeton University | BBC | Schmidt Ocean Institute | Scientific American | University of Aberdeen | Popular Science | NPR
