This month NASA's Perseverance Rover lands on Mars to search for life on the Red Planet. But Lisa Fletcher reports: the search out there has a connection to research for unknown life forms in the deepest and darkest places on planet Earth.
From the time humans first looked up into the stars, there’s been one burning question above all others: is there life out there?
NASA has long studied the planets and moons, searching for key ingredients needed for life.
Probes and landers have been sent to look for the telltale signs. Plenty of successes and tantalizing evidence had been gathered.
Still, a big part of the challenge: figuring out not just where to look, but also what to look for, which is why I’ve come to meet Dr. Chris German, a world-renowned scientist at the Woods Hole Oceanographic Institution in Massachusetts. He’s an expert on earth’s deep oceans, which as it turns out, means he also knows a lot about how to find life in places much further away.
Lisa: So, you can't get much farther apart than the depths of the ocean and outer space.
Chris: Well, in the last 20 years, one of the biggest discoveries NASA has made is that they actually have a whole bunch of oceans to worry about in the outer solar system.
German and others here are now working side-by-side with space scientists looking for life -- out there.
Chris: If you go out beyond what's called the ice line in the solar system, out from Jupiter and outwards, there are a whole series of moons each of which have saltwater oceans just like ours, and a good subset of those have rocky sea floors as well.
Woods Hole scientists have spent decades studying the deepest parts of our oceans in deep submersibles like “Alvin,” which has been blazing a trail of discovery since the mid-1960s. Though it’s most famous for diving on the Titanic, it was a discovery made with the help of this sub in 1977 that set the stage for NASA’s interest in our oceans.
Chris: There's a whole way you can sustain life on our planet that doesn't need sunlight. That it can be driven by geothermal energy from the interior working of a planet.
That geothermal energy takes the form of hydrothermal vents --cracks in the seafloor where cold ocean water gets super-heated by magma releasing chemicals and minerals-- and, amazingly, sustaining microbial life without a single ray of sunlight.
Not unlike what NASA scientists expect to find on planets and moons in our solar system.
Chris: The water on the outside of the moons and planets is frozen, but underneath that, you have liquid water. If any of those planets are geologically active, and we know some of them are, then there's no reason why you couldn't have the same kind of geothermal hot springs at the sea floor, which certainly means that they should be habitable.
At NASA’s Goddard Space Flight Center in Maryland, research space scientist Dr. Melissa Trainer is focused on finding those life-sustaining habitats in the solar system.
Dr. Trainer: It's thought that life on earth started in its oceans, so it's natural to think that the most likely habitat for finding life off of earth would also be an ocean. And when we want to understand, well, could there be life in these oceans, could they be habitable and if so, what would we be looking for, it's very obvious that we'd want to turn to the experts on oceans and ocean life for our own planet.
For Dr. Trainer and others at NASA, the leading candidates where we might find evidence of life are the moons Europa, Enceladus, and Titan.
Dr Trainer: Titan has everything we think of as being important for life as we know it. It has an energy source. It has organic molecules and nutrients, and it has liquid water in a subsurface ocean as well as times in the past where liquid water has existed on the surface. And actually, there are polar seas at Titan that are made up of liquid methane and ethane and they behave a lot like the seas on earth and they create, like I said, a similar cycle you can get on earth and it's possible that’s a medium for weird exotic life.
She’s now working on plans for a mission to titan called dragonfly, due to launch in 2026, that’ll survey the surface for chemical and geological signs that Titan could support life.
Ocean scientist Chris German sees NASA’s challenge as similar to the one he faces.
Chris: Where we're at right now is that NASA have identified that the best chance we have in the next human generation to find life beyond the earth, is by exploring remote and poorly explored deep oceans. Turns out oceanographers have the same problem. Earth is covered by loads of deep and unexplored remote oceans.
So, exploring more of our own oceans is now a top priority, and to do that, ocean scientists have enlisted the help of cutting-edge technology to produce new fleets of autonomous underwater vehicles, so they can explore faster and farther than before.
Mechanical engineer Molly Curran is one those helping design the new vehicles, and like her scientist colleagues, she’s also partnering with NASA.
Molly: We are designing these robots to go down and study our own Earth's ocean so that we know more about them, we know more about the biology, the chemistry, everything that's going on and how that affects our own earth. But at the same time, we're building these platforms that can enable us to go to possibly other ocean worlds in our solar system.
The aim one day, to have something like a fleet, of underwater drones.
Molly: Instead of having one large vehicle, that's one set of eyes looking on the ocean floor, one day we hope to have a fleet of these vehicles, so that we have all these eyes exploring, covering so much more ground, and learning more than just having one large vehicle down there.
A race to learn all we can about life on our own world, so we can have the best chance of finding life out there.
For Full Measure, I’m Lisa Fletcher.