NASA’s Europa mission is a homecoming for a planetary astronomer

Planetary astronomer Bonnie Buratti remembers exactly where she was the first time she heard that Jupiter’s icy moon Europa might host life.

It was the 1980s, and Buratti was a graduate student at Cornell University studying images of the planet’s moons taken during the Voyager 1 and 2 flybys in 1979. Even in those first low-resolution pictures, Europa was intriguing.

“It looked like a cracked egg,” she says.

Those cracks — in a snow-covered, icy shell — were probably filled with material that had come up from below, Buratti and colleagues had shown. That meant there had to be something under the ice.

Buratti recalls his graduate student, Steven Squyres, talking about the possibility that Europa’s ice might hide a liquid salty ocean. “He said, ‘Well, there’s an ocean down there, and where there’s water, there’s life,'” she recalled. “And people laughed at him.”

They’re not laughing anymore.

Over the past four decades, Buratti has seen the search for life in the solar system go from a joke to a major mission. She is now deputy project scientist for NASA’s Europa Clipper mission, which launched on October 14 to find out if Europa is indeed a habitable world. (SN: 10/8/24).

“I’m coming home,” she says.

Space science first captured Buratti’s imagination in childhood, which coincided with the beginning of the space age. She was a child when the Soviet Union launched Sputnik and a teenager when Apollo 11 landed on the moon.

“I got a telescope when I was in third grade,” she says. She remembers discovering the constellations from her front lawn in Bethlehem, Pa. “From a young age, I was always curious.”

Planetary science attracted him to the biggest personalities in the field. In graduate school, she worked with famous scientists, including Frank Drake and Carl Sagan, who were at the forefront of efforts to take the search for extraterrestrial life seriously (SN: 1/11/09; SN: 11/7/14). This gave her a sense that the universe might teem with life, but not the support she needed to get through her Ph.D. She ended up working with the less famous but equally charismatic astronomer Joe Veverka. It was Veverka who gave her the Voyager images.

Buratti joined NASA’s Jet Propulsion Laboratory in Pasadena, California, in 1985 and has been there ever since. But while the Galileo spacecraft was finding evidence of Europa’s subsurface ocean in the 1990s, Buratti was busy exploring Saturn with the Cassini mission (SN: 18.2.02).

Saturn’s moons were full of surprises, including ghostly hydrocarbon lakes on Titan, water plumes from Enceladus, and a mysterious ridge that makes Iapetus look like a nut (SN: 15.4.19; SN: 8/4/14; SN: 21.4.14). “It was just one thing after another,” says Buratti.

These discoveries helped advance the notion that subsurface oceans in the solar system might not be so strange after all. Hints of oceans have since appeared as far from the sun as Pluto, Buratt’s favorite planet — and yes, she still calls it a planet (SN: 27.3.20). There may also be oceanic worlds orbiting other stars.

So when the Europa Clipper reaches Jupiter in 2030, scientists are looking at this moon as an example of worlds that may be common in the universe. Clipper will orbit Jupiter and make at least 49 flybys of Europa to limit the amount of time the spacecraft spends in Jupiter’s punishing radiation belts. Measurements of the moon’s surface composition, gravity and internal structure will be needed to assess how suitable the small world is for life.

Buratti joined the Clipper mission in 2022, as one of the people charged with making sure the team gets as much science out of the mission as they can. “We’ve always felt that our role is to improve the science, to get the best science out of the mission,” she says. She and the scientific community at large are confident they will find something good.

“We are very confident that there is a habitable environment,” she says. Echoing that grad school speech from decades ago, she adds, “On Earth, wherever you see water, you see life. So I think it’s a really good place to look.”