Alien Quest

For astrobiologist Kevin Peter Hand ’97, the search for extraterrestrial life begins under the ice on planet Earth.

About a mile from the Red Shed, the living quarters shared by Kevin Peter Hand and about 90 others at Casey Station in Antarctica, the NASA crew had cut a square hole in the ice exposing the frigid waters below. Every few days Hand and his team would ride snowmobiles to the site to drop their underwater robot into the water and let it roam the underbelly of the ice.

It didn’t take long for Hand and his team to attract spectators. While working at the site one morning, Hand looked up to find a group of Adélie penguins warily eyeing the NASA scientists from a nearby embankment. Inquisitive by nature, the penguins quickly grew accustomed to the team’s presence and would frequently wander into the test site to get a better look at the action. The bizarre encounters amused Hand.

“Here we have these sapiens wrenching away on their robot, which has a bit of intelligence in its onboard brain so it can try to better understand organisms in the ocean, and these curious birds wander up to us to see what the heck is going on,” Hand recalls. “It’s organisms studying organisms studying organisms.”

Many people assume Antarctica’s ocean is a barren, lifeless place. Compared with Earth’s other oceans, it certainly is. You won’t find the dazzling reefs and rainbow fish native to warmer climates, but Antarctica has a diverse aquatic ecosystem home to gigantic algae blooms, krill, sea stars, and many other creatures that don’t mind the cold. Although scientists are just beginning to understand the dynamics of life in Earth’s frozen ecosystems—known as its cryosphere—it’s abundantly clear that life can thrive in far more extreme conditions than was thought possible just a few decades ago.

“People assume there is little under the surface because it looks so extreme with all the ice and not a lot is visible, but they couldn’t be more wrong,” says Peter Convey, a terrestrial ecologist and expert in polar environments with the British Antarctic Survey. “The seafloor community found in many parts of the continental shelf and coastal regions around Antarctica has been called second only to coral reefs in its species richness and biomass.”

As Hand describes in his new book, Alien Oceans: The Search for Life in the Depths of Space [read an excerpt here], the Antarctic biosphere has big implications for the search for life beyond Earth. The search for extraterrestrial life in our solar system has historically focused on Mars, which is believed to have once had a large liquid water ocean and an atmosphere as thick as Earth’s. But now that we know life can thrive beneath Earth’s ice caps, several icy moons in the outer solar system seem to be fertile alien hunting grounds. These so-called “water worlds” are believed to harbor vast oceans beneath their thick, icy shells. 

If there’s life beneath the ice in Antarctica, the thinking goes, perhaps there’s life beneath the ice there, too.

Hand helped invent a robot named BRUIE—Buoyant Rover for Under-Ice Exploration—which collects data as it crawls along the underside of frozen lakes. (Photo by Mark Thiessen/National Geographic Creative)

Hand had not been to Antarctica in nearly 20 years, and when he returned this past November it wasn’t as he remembered. It was too...warm. It had been colder at his childhood home in Manchester, Vermont, than it was on the base the previous time he had visited. Now temperatures on the frozen continent were hovering at just under 5 below zero—positively balmy by Antarctic standards. This was bad news. Hand and his NASA colleagues had flown to Casey Station, one of Australia’s three Antarctic outposts, for a three-week sojourn to test their new underwater robot. But if temperatures rose any higher, Casey’s runway would become too soft for planes to take off and carry the team back to civilization. 

“It was very disconcerting,” Hand says. “It was still cold, but more like a sunny, cold spring day in the White Mountains than a day on the shores of the coldest place on Earth.” 

Temperatures breached 5 degrees below by the end of Hand’s second week at Casey, and the NASA team had to cut its stay short. But it had accomplished what it set out to do. The robot had worked like a charm on its first missions beneath the Antarctic ice and pointed to a promising new direction for the exploration of oceans both on and off the earth. Hand hopes this robot’s progeny will be the first to encounter extraterrestrial life. 

Magic of the Skies
Hand has always been fascinated with the possibility of extraterrestrial life, an obsession he attributes to growing up under the star-studded Vermont night sky. Hollywood sci-fi also played a role. “I read Carl Sagan’s books and watched Cosmos repeatedly,” says Hand. “ET made a huge impression, too. I wanted to be Elliott, and I always hoped that someday I’d go into the woods behind our house and find an alien spaceship.”

As a devotee of Sagan’s brand of extraterrestrial evangelism, Hand arrived at Dartmouth in 1993 determined to turn alien hunting into a career. He made an unusual choice of a double major—physics and psychology—both essential tools in this pursuit. The training in physics would help him find the aliens; psychology would help him communicate with them. Some of Hand’s physics professors gently tried to persuade him to take up a more “serious” occupation. 

But Hand found a sympathetic ear in the late Jack Baird ’60, a professor of psychology who had advised NASA on the agency’s search for extraterrestrial life. Baird’s book on the subject, The Inner Limits of Outer Space, still sits on a shelf in Hand’s office in NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, where he works on the cutting edge of the search for alien life—albeit of the non-intelligent variety. 

Hand spent most of his free time at Dartmouth with the Outing Club exploring the White Mountains or climbing around the United States with the Mountaineering Club. On occasion it could be difficult to balance his passion for astronomy with his thirst for exploration. Hand’s thesis advisor, physics and astronomy professor John Thorstensen, recalls traveling to Kitt Peak National Observatory in Arizona when Hand was a senior to conduct research. Thorstensen and Hand returned from the trip just a few hours after the Outing Club set out on its annual 54-mile hike to Mount Moosilauke. Undeterred, Hand set out on his own that same night to try to catch up with the group.

“He was determined to do this hike,” Thorstensen says. “He didn’t quite make it to Moosilauke, but he made it a long way. He was a person with a lot of energy, focus, and drive.”

When Hand was a senior, Thorstensen gave him a key to the College’s Shattuck Observatory, which quickly became something of a second home. Hand would bring his sleeping bag to the observatory and, after a long night watching the cosmos, he’d fall asleep outside beneath the statue of Robert Frost, class of 1896, scratching away on a notepad. Hand credits the clear night skies of the Northeast with stoking his passion for the search for life beyond Earth. “You just can’t help but question if we’re alone when you sleep out under those stars.” 

In December 1995, NASA’s Galileo spacecraft began its orbit around Jupiter and then spent almost the next decade studying the gas giant and its moons. Europa, Jupiter’s fourth-largest moon, proved to be of particular interest. Evidence from Earth-based telescopes and Galileo suggested that Europa harbored a planet-wide liquid water ocean beneath its thick icy crust. Some scientists went so far as to propose that conditions in Europa’s oceans might sustain prebiotic molecules or perhaps even simple life forms. At the time it was a controversial opinion, but today many planetary scientists agree that if there’s extraterrestrial life in our solar system, Europa is the best place to find it.

More than 400 million miles from where Hand dozed beneath Frost’s unwavering gaze, Galileo continued to collect data that built a case for an ocean on Europa. It would be years before the significance of the data was fully understood, but the spacecraft ultimately shaped the course of Hand’s career. 

After graduating, Hand moved to California and did a brief stint as a research assistant at the SETI Institute, a nonprofit organization in Silicon Valley dedicated to the search for intelligent alien life. In 2001 he enrolled at Stanford to pursue a master’s in mechanical engineering that focused on robotics. Shortly thereafter, Hand enrolled as a doctoral student in Stanford’s geological and environmental sciences program. His dissertation was about the physics and chemistry of Europa’s ice shell and subsurface ocean. By this point, it was established that Europa was the most likely place to support extraterrestrial life in the solar system, and Hand was determined to help find it.

But in 2003 Hand received a call that put his Ph.D. ambitions on hold. It was from his friend George Whitesides, who now serves as CEO of the space tourism company Virgin Galactic, and he had a remarkable proposition. James Cameron, director of Titanic and The Terminator, was going on an expedition to the bottom of the ocean. He wanted to make a film about life in the deep sea and what it implied about the possibility of life on Europa. Was Hand interested in joining Cameron on the journey?

“At first, I didn’t want to go,” Hand says. “I thought it would be a distraction from my Ph.D. and the work I was doing.”

While most people would jump at the chance to explore Earth’s last uncharted regions with a Hollywood A-lister, Hand was conflicted. The adventure with Cameron would take months. After a conversation with his friend and mentor, microbiologist Ken Nealson, Hand accepted the offer. As he recounts in Alien Oceans, the two were standing on a dock one evening on Catalina Island, California, when Nealson grabbed Hand’s shoulder and offered some sage advice. “You’re overthinking it,” Nealson said. “If there’s even the slightest chance you get to go to the bottom of the ocean, you better go!”

So, less than a month after taking the call from Whitesides, Hand found himself on a Russian research ship in the middle of the Atlantic, preparing to dive 2 miles below the surface of the ocean. The plan was to explore Menez Gwen, a seamount covered with hydrothermal vents spewing a blazing hot and nutrient-rich sludge from deep in the Earth into the ocean. Cameron and Hand would descend in separate submersibles with two other team members and during the course of nine dives would spend hours roaming the ocean floor and collecting samples. 

“Those experiences on the sea floor changed my life forever.”

What Hand saw at the bottom of the ocean was Earth’s own alien world. At these depths the darkness is total, temperatures hover near the freezing point, and pressures are 350 times greater than at sea level. It’s the last place on Earth you’d expect to find life, but Hand found a thriving ecosystem clustered around the thermal vents. On the surface, life is dependent on light to drive photosynthesis and provide the energy for plants and microbes. But at the bottom of the ocean, microbial life feeds on the molten metals delivered from deep in the earth, and these microbes form the basis of the deep sea food chain.

“Ken was absolutely right,” Hand says. “Those experiences on the sea floor changed my life forever.”

Hand already knew there was life on the bottom of the ocean, but as he gazed out from the submersible, he was struck by the profound implications of what he was seeing for his own work on Europa. “The scene through that porthole could be what ‘home’ looks like to most life in our universe,” Hand writes in Alien Oceans. The microbes and sea creatures at the bottom of our own ocean may be able to thrive in the salty waters of Europa or other water worlds in the solar system. “Deep, dark, seemingly desolate ocean floors may be some of the best real estate for biology.”

If Hand is right, an abundance of life could be waiting to be discovered in the oceans beneath the frozen surfaces of other planetary bodies. Now he’s building the tech to help find out.

Next Stop, Europa
When he’s not in Antarctica, Hand usually can be found working as a coinvestigator on NASA’s upcoming Europa Clipper mission. In 2025 NASA will send the spacecraft on the first dedicated mission to the Jovian moon, where it will spend at least three years taking pictures of the surface and probing beneath the ice with ground-penetrating radar. Europa Clipper is the largest spacecraft ever to venture into deep space. It will be packed full of instruments, some of which will be able to detect chemical signatures of life on Europa if the spacecraft happens to fly through a plume of water erupting from the moon’s surface.

Evidence pointing to the existence of life on Europa could then compel NASA to send a robot to its surface. During his time at JPL, Hand has worked on two Europa lander concepts, but neither has been tapped to proceed from concept to hardware. It’s not for a lack of engineering know-how; Hand says the technology is ready if NASA decides to fund a Europa lander tomorrow. Instead, missions to Europa’s surface have been stymied by politics and competing scientific priorities.

Given the bureaucratic roadblocks to a Europa lander, Hand estimates it could be 30 years before human technology touches down on the surface of the Jovian moon and perhaps another 30 years before there’s a mission beneath the surface. While some might be discouraged by these time frames, Hand doesn’t let it get him down. “I like to view these big missions as the cathedrals of our day,” he says. “They are generational tasks, and I feel fortunate to be a part of that.”

In the meantime, Hand is testing prototype Europa explorers on Earth. Since 2011 Hand and his colleagues at JPL have been working on the Buoyant Rover for Under-Ice Exploration, or BRUIE, a small robot that looks like a rugged version of a toy hoverboard. Its meter-long body is essentially an orange, hexagonal axle flanked by wheels covered with gear-like teeth, which it uses to slowly crawl along the underside of the ice. A small pole laden with sensors protrudes from the middle of its body, where onboard computers run sophisticated machine-learning algorithms to help the craft autonomously navigate underwater.

As one of BRUIE’s inventors, Hand was intimately involved in its creation. In the early days of the rover’s development, Hand helped with everything from sensor integration to writing BRUIE’s code. Now that the team has grown, Hand says he has taken on a leadership role to ensure that the robot can meet the team’s scientific goals and is ready for deployment in the field.

In many respects BRUIE is a spacecraft for Earth. Hand says the rover repurposes a lot of hardware and software used in small satellites. “When it comes to the exploration of distant worlds, one of my passions is that it also helps us better understand our own planet. NASA has invested tens of millions of dollars into space applications, so let’s take some of that and use it to explore our own ocean.” 

BRUIE is a dramatic departure from other NASA-funded robots that have probed Antarctica’s ocean in the past. Most have been submersibles, which are designed to sink to a desired depth and use propellers to swim through the water. BRUIE, by contrast, is designed to float. This allows it to ditch the propeller and roll along the ice, conserving the robot’s limited energy supply and preventing its movements from disturbing the fragile aquatic ecosystem the robot is meant to study.

Hand and his colleagues at JPL have conducted numerous tests of a supercharged version of BRUIE in Alaska, where it is used to study lakes that contain unusually high amounts of methane. There, BRUIE has demonstrated the ability to roam the undersides of frozen lakes untethered and beam data up to satellites. The version that Hand brought to Antarctica is relatively unsophisticated by comparison. It stays attached to a tether that is used to relay data and never ventures more than 300 feet away from where it is deployed. Since this was BRUIE’s first time in Antarctica, Hand and his colleagues wanted to play it safe. 

“We were quite nervous, but, thankfully, everything worked beautifully,” Hand says. “It was also quite a relief not having to constantly look over our shoulders for polar bears; down in Antarctica all we had to worry about were the adorable, and incredibly curious, Adélie penguins.” 

Hand’s team deployed the rover half a dozen times in Antarctica on missions that lasted up to three hours. BRUIE was flexing its mechanical muscles in a new environment, proving to Hand and his colleagues that it could collect data on the salinity and oxygen levels and temperatures of the water, while also taking high-definition pictures. Hand says the bot performed flawlessly, and the researchers eventually grew comfortable enough with its performance to let it crawl around unsupervised for 48 hours.

“Building and testing robotic vehicles in the field is always a highly iterative evolution process fueled by insomnia and caffeine,” Hand says. “Often we think we’ve moved one step forward, but then we discover we actually moved two steps backward. That’s what makes this process so important. In the field we can pull the robots out and re-solder a wire or replace a sensor. In space that’s not an option.”

Absent plans to land on Europa, it’s entirely possible that BRUIE will never see an alien shore. In the meantime, Hand says, there’s a lot the robot can do on Earth to help us better understand the woefully understudied cryosphere. It’s an urgent task. Convey, of the British Antarctic Survey, says climate change creates multiple threats to Antarctic ecosystems and species, such as habitat loss and declining populations. Without robots such as BRUIE, researchers may never have a chance to study these ecosystems before they’re gone.

Hand hopes that there will be more missions to Antarctica to test even more sophisticated versions of BRUIE in the future. He envisions an armada of robots like BRUIE crawling under the polar ice caps for months on end, studying changes in this unique environment. “At NASA we build these robotic vehicles that survive for decades in space or roaming the surface of Mars,” Hand says. “Why don’t we have robotic vehicles swimming around in our own ocean investigating the sea ice and surviving for years on end?”

For now, this remains a distant dream. But Hand’s work in Antarctica is an important step toward a deeper understanding of life on our own planet—and beyond.            

Daniel Oberhaus is a staff writer at Wired, where he covers space exploration and the future of energy, and the author of Extraterrestrial Languages (The MIT Press 2019).

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