Gunky, Snotty Extremophiles Could Point To Life On Moon Of Jupiter
Here are the basic building blocks of most life as we know it: carbon, energy, and water. But if you’re looking for signs of life in space – you need to change how you think about life itself.
That’s where the Brazelton Lab at the University of Utah comes in. They study extreme microbes here on Earth -- with an eye towards the sky. KUER’s Elaine Clark sat down with Julia McGonigle, an astrobiologist working on her PhD in the lab. She’s explored Utah’s West Desert and a place deep in the Atlantic Ocean called the Lost City.
Elaine Clark: Introduce us to the Lost City. Where is it? What does it look like?
Julia McGonigle: So, the Lost City is on the mid-Atlantic ridge and smack dab in the middle of the Atlantic Ocean. It's about 900 meters deep. If you were to jump in a submarine and go down there, you would be in a sea of darkness. And as you came upon it you would start to see these towering white chimneys. They kind of look like cave formations like stalactites. It's just kind of jutting up out of a mountain in the ocean.
Elaine Clark: How do the conditions there differ from what we would understand about the usual conditions for underwater life?
JM: So the conditions at Lost City are interesting because they're continually bathed in these special fluids called serpentinite fluids — which is really a big fancy word just to say that this special type of rock meets the water and a reaction occurs and the fluids heat up. They get really hot.
A lot of hydrogen is released. A lot of methane is released and the pH is changed to a really high pH. Most of life forms that we know wouldn't be able to live there. High temperatures are usually a problem for life. Also, high pH can be a huge problem for life.
EC: How did you go about looking for life there?
JM: So, the first expedition to The Lost City was in 2000 and a remote submersible submarine dove down there and sort of serendipitously discovered these crazy cool chimneys. And you can see these — what are called biofilms — just covering the chimneys. So you could see these stringy, snotty, waving, gunky things which are similar to algae. If you think of like a crust on algae in a pond scum or something like that. So we see that and as biologists we think, “Oh, that's life.”
EC: What's it like looking at that world for the first time?
JM: So I was there in September of last year 2018. This expedition was led by chief scientist Susan Lange.
It was really bizarre to actually be on the ship looking at it. We go into this sort of shipping container that's built up really intensely to control this remote submersible, and the panel in front of you is covered in screens. There are a lot of things going on and a lot of really excited people in the room. And then you stumble across this world and the chimneys start to glow in the lights and you're just kind of in awe. Like this is why we're suffering. This is why we sat through hurricanes on a very “rolly” boat for two weeks is to get here and to be able to do some science here that nobody has done yet.
EC: These biofilm sheaths — what are we learning from them?
JM: We're learning what types of organisms are living in these extreme environments. How they're living. What types of fuel are they using to make energy? What types of carbon sources are they using to eat food? We're interested in how they're interacting with each other. So are these communities cooperating? Or certain cells doing one thing and then helping out another cell by doing this thing?
EC: So that's one extreme location …
JM: Yeah. So, another site that I work on is the Bonneville Salt Flats You don't see any plants. You don't see any algae. You don't see anything. But if you took a shovel and dig down past the salt crust, you'll start to see these interesting colors kind of woven into the salts. You'll see pinkish colors and greenish colors. And these are really exciting for a microbiologist because we see colors like that and we think, “Oh, cool — life!”
EC: So what are the environmental conditions there in those layers of salt that are different from the way we typically understand how life exists?
JM: Salt is a huge problem for life because it prevents the way the inner workings of the cell function. And so the cells that are living in these salty environments have to make really cool adaptations so that they basically still work. If you think of people that are stranded out at sea and they have nothing but salt water to drink, they get dehydrated. Your body can't process that.
EC: What would happen to us if we were in the Lost City?
JM: The pressure is so intense there that we wouldn't be able to exist. We would basically die and probably not look very pretty after. But also, if you think about the pH being really high. If you took a human and stuck a human in a bath of like pH 10, they're going to get burns. It's essentially the same as getting an acid burn except it's a base.
EC: How then do you take this information and go about looking for this kind of life in space.
JM: We use an environment that's analogous to what we're looking at. So, if we think about the salt flats, we know that salt flats are on Mars. So, we would send our Curiosity Rover over there and dig into the soil and take a sample and look for signatures of life. We haven't done that yet because we don't actually think there's enough water on the salt flats on Mars for life to exist in those particular locations.
For the Lost City, we know that these rock-water interactions are happening on other places in the solar system. We think this is going on around one of the moons of Jupiter called Europa. We know that type of rock is there. We know water is there. We know that this reaction will go when there's rock and water.
EC: What excites you about this research?
JM: I think just the natural wonder of it. I am personally an explorer. I like to go out into the wilderness and explore things. And when I think of these environments, it's just exciting to think about how few humans have been there.
There is a real value to this. One, just for expanding the knowledge because it’s interesting. But two, because you end up finding technologies — useful things in this type of work that you would never have even imagined — like the technologies in your cell phone, the potential of new classes of antibiotics.
And I think the desire to find life on another planet is maybe a little bit philosophical. It would be a little bit comforting to know that there is another planet out there that can support life. We don't want to be the only ones alone in this vastness of the universe.
Julia McGonigle is an astrobiologist studying extremophiles at the University of Utah.