• Scientists believe Europa's seafloor is likely tectonically quiet, without active volcanoes or hot water plumes.
• These findings contrast with the long-held theory that Europa is a promising location to find extraterrestrial life.
• NASA's Europa Clipper spacecraft is currently en route to the moon to investigate its potential for habitability.

Jupiter's moon Europa has long been shortlisted among scientists as one of our solar system's most promising locations to search for life – or, at least, the conditions that could support it.

But a new study has cast doubt on the idea that the intriguing world shrouded in ice could indeed harbor extraterrestrial life deep in its vast ocean of liquid saltwater.

By studying the moon's size, the chemical makeup of its rocky core and the gravitational forces at work from the gas giant Jupiter, a team of scientists came to a conclusion that may be dispiriting to those searching for life beyond Earth. Europa, they say, likely lacks the underwater geologic activity that would be necessary for life, according to a press release Tuesday, Jan. 6, unveiling the findings.

That could be unwelcome news for NASA, which in 2024 sent a spacecraft on a years-long journey to investigate the moon for signs that life could thrive beneath its icy surface.

Here's everything to know about the new findings.

What is Jupiter's moon Europa?

The fourth largest of Jupiter’s 95 moons, Europa is an icy celestial body that scientists have long suspected could harbor the conditions necessary to support life beneath its surface.

Though Europa is slightly smaller than Earth’s own moon and barely one-quarter the diameter of Earth, beneath its cracked, ridged surface is a vast salty ocean that could be up to 100 miles deep – or twice the size of Earth’s own oceans combined. Scientists have long theorized that the icy crust above the ocean conceals evidence of organic compounds and energy sources – the ingredients to life.

Study casts doubt on habitability of Europa

A new study lead by Paul Byrne, a planetary scientist at Washington University in St. Louis, Missouri, suggests that Europa may be home to a tectonically quiet seafloor that wouldn't support contemporary life beneath the ice.

Because scientists can't exactly board a submarine to study Europa's seafloor, the researchers instead combined known facts about Europa with inferences drawn from the geology of Earth and other bodies, including our own moon. The processes they considered are ones that on Earth jump-start the production of nutrients and chemical energy that are essential for life.

“If we could explore that ocean with a remote-control submarine, we predict we wouldn’t see any new fractures, active volcanoes or plumes of hot water on the seafloor,” Byrne said in a statement. “Geologically, there’s not a lot happening down there. Everything would be quiet.”

While Earth’s core still burns hot, Byrne and the co-authors calculated that any heat from Europa’s core would have escaped billions of years ago. What's more, the tidal forces that make the Jovian moon Io the most volcanically-active body in our solar system aren't present at Europa – meaning, the researchers claimed, it may not be "geologically alive."

The study was published Tuesday, Dec. 6, in the journal Nature Communications.

NASA spacecraft on way to search for signs of life on Jupiter moon

NASA, meanwhile, already has a spacecraft en route to Europa to search for signs that the planet could sustain life.

The Europa Clipper, the largest uncrewed vehicle NASA has ever developed for a planetary mission, launched in October 2024 from Florida on a mission that will see it arrive in Jupiter's orbit in 2030. Ahead of the spacecraft is a 1.8 billion-mile journey to Europa on a trajectory taking it past Mars and then Earth, using the planets’ gravity as a slingshot to add speed to the trek. 

Spanning 100 feet from end to end, the orbiter is due to then spend four years mapping and scanning above and beneath Europa's surface over the course of 49 flybys.

Astronomers believe ocean worlds such as Europa are common outside of our solar system, so studying the icy moon could prove to be the first step to understanding how life could exist beyond Earth.

Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at elagatta@gannett.com