Autonomous drones could search for life in Europa’s subsurface ocean
Autonomous drones capable of making their own decisions could someday be used to search for signs of life in the subsurface oceans of icy outer Solar System worlds such as Europa. As part of an ongoing research project aimed at developing robotic submersible drones, researchers representing NASA and several other institutions recently tested six drones, using them to study changes in temperature and salinity beneath the waves of Monterey Bay, California.
Coordinated to work together as a fleet, the drones traveled for miles. They faced hazards such as potentially corrosive saltwater, entanglement in forests of kelp, and even sharks, who at times attempted to bite their wings.
In spite of these hazards, submersible drones are now frequently used for ocean research because satellites are only capable of studying ocean surfaces – their signals are unable to penetrate subsurface water. For NASA, artificially intelligent submersible drones could represent one of the best options in terms of searching for underwater signs of life on other worlds.
Unlike the drones that explored the waters of Monterey Bay, those sent to find life in the subsurface waters of other worlds would have to be capable of plotting their own journeys underwater based on what they detect in their immediate environments.
The drones that explored Monterey Bay relied on reports of ocean features communicated to them from the shore.
“Autonomous drones are important for ocean research, but today’s drones don’t make decisions on the fly,” explained research team member Steve Chien, who leads the Artificial Intelligence Group at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. “In order to study unpredictable ocean phenomena, we need to develop submersibles that can navigate and make decisions on their own, and in real-time. Doing so would help us understand our own oceans – and maybe those on other planets.”
Even detailed study of Earth’s oceans requires drones capable of piloting themselves without human interaction so they can concentrate on collecting data, according to Andrew Thompson, a Caltech assistant professor of environmental science and engineering.
Searching for Life
Especially important for detecting signs of life is the ability to track the smallest levels of ocean life, such as the nutrients needed to support plankton.
These nutrients, or minuscule levels of life, exist in the form of “biocommunities” that are challenging to find because they are constantly swept by ocean currents, which can change their directions very suddenly.
Living organisms such as small fish can naturally track plankton, but robotic drones currently do not have this ability.
“It’s all three dimensions plus time,” Chien explained, regarding the difficulties of tracking underwater life. “Phenomena like algal blooms are hundreds of kilometers across. But small things, like dinoflagellate clouds (clouds of single-celled organisms with two flagella or threadlike appendages), are just dozens of meters across.”
Conducted earlier this year, the test in Monterey Bay was funded by JPL and by Caltech’s Keck Institute for Space Studies (KISS).
In addition to scientists from JPL and Caltech, researchers representing the Monterey Bay Aquarium Research Institute in Moss Landing, California; Woods Hole Oceanographic Institute of Woods Hole, Massachusetts; and Remote Sensing Solutions of Barnstable, Massachusetts, participated in the project.
Thompson expressed hope that joint efforts by JPL and the artificial intelligence community will lead to the development of autonomous drones that can be used for future planetary explorations. Research toward that end will continue next year.
“Truly autonomous fleets of robots have been a holy grail in oceanography for decades,” Thompson stated. “Bringing JPL’s exploration and AI experience to this problem should allow us to lay the groundwork for carrying out similar activities in more challenging regions, like Earth’s polar regions and even oceans on other planets.”
Laurel Kornfeld is an amateur astronomer and freelance writer from Highland Park, NJ, who enjoys writing about astronomy and planetary science. She studied journalism at Douglass College, Rutgers University, and earned a Graduate Certificate of Science from Swinburne University’s Astronomy Online program. Her writings have been published online in The Atlantic, Astronomy magazine’s guest blog section, the UK Space Conference, the 2009 IAU General Assembly newspaper, The Space Reporter, and newsletters of various astronomy clubs. She is a member of the Cranford, NJ-based Amateur Astronomers, Inc. Especially interested in the outer solar system, Laurel gave a brief presentation at the 2008 Great Planet Debate held at the Johns Hopkins University Applied Physics Lab in Laurel, MD.