The giant planet Jupiter has nearly 100 known moons, but none has captured scientific attention quite like Europa, which likely hides a global salty ocean beneath an icy crust that may contain twice as much water as all of Earth's oceans combined. A new modeling study led by Washington University in collaboration with Woods Hole Oceanographic Institution (WHOI) suggests that, despite this ocean, Los Angeles CA (SPX) Jan 21, 2026
The giant planet Jupiter has nearly 100 known moons, but none has captured scientific attention quite like Europa, which likely hides a global salty ocean beneath an icy crust that may contain twice as much water as all of Earth's oceans combined. A new modeling study led by Washington University in collaboration with Woods Hole Oceanographic Institution (WHOI) suggests that, despite this ocean, Europa's seafloor probably lacks the vigorous tectonic and volcanic activity that powers dramatic hydrothermal systems on Earth.
The research team used models that accounted for Europa's size, rocky interior, long-term cooling, and the powerful tidal forces exerted by Jupiter to assess whether the moon's seafloor could sustain modern-day volcanism. Their calculations indicate that the rocky core should have cooled substantially over the age of the solar system, making it resemble Earth's present-day Moon more than Earth's geologically active seafloor. As a result, the study concludes that Europa is unlikely to host intense seafloor volcanism and classic "black smoker" hydrothermal vent fields like those that dot mid-ocean ridges on Earth.
"Our study shows that there might not be a lot happening down there, from a geophysical perspective," said Chris German, a WHOI senior scientist and co-author of the study. The apparent lack of vigorous tectonic activity at Europa's seafloor aligns with spacecraft observations of the moon's icy surface, which show limited signs of recent large-scale geological disruption. Taken together, these lines of evidence point to a relatively quiet rocky interior today.
Lead author Paul Byrne, an associate professor of Earth, environmental, and planetary sciences at Washington University, noted that Europa still experiences some tidal heating, which helps prevent the ocean from freezing solid and may have been stronger in the distant past. "Europa likely still has some tidal heating, which is why it isn't completely frozen, and it may have experienced much more heating in the distant past," Byrne said. "But we don't see much evidence of active geology on Europa's icy surface today. Our calculations suggest that the geological processes operating at the seafloor, considering tides, long-term interior cooling, and mantle convection, aren't strong enough to drive significant activity right now."
Despite this apparent quiescence, the new work points to an alternative pathway for sustaining habitable conditions beneath Europa's ocean. "What our work at WHOI has shown is that so long as Europa's seafloor has been geologically active in the past," German said, "it could still have more than enough capacity to host lower-temperature forms of fluid flow, also well-known on Earth, that could underpin a geothermally-driven food chain." Instead of intense, high-temperature black smokers, Europa may support more diffuse, lower-temperature hydrothermal circulation that can still release nutrients and support chemical energy sources for life over long timescales.
With no way yet to directly probe Europa's seafloor, the study relies on combining known properties of the moon with analogs from Earth's geology and experience from other planetary bodies. This approach allows scientists to constrain how much internal heat is likely available today and how that heat might drive fluid circulation through the rocky crust beneath the ocean. Even if current heat flow is modest, long-lived low-temperature systems could continue to alter rocks, release dissolved chemicals into the ocean, and sustain redox gradients that potential microbial ecosystems could exploit.
The findings feed directly into a new five-year, 5 million dollar NASA project that WHOI has been selected to lead, called Investigating Ocean Worlds. This initiative brings together experts from 16 U.S. laboratories to study how organic compounds are generated and altered as they travel through the subseafloor of ocean worlds, move upward through their oceans, and eventually reach icy surfaces, where future spacecraft could detect them. By tracing these pathways, the project aims to link deep interior processes to surface signatures that remote missions can measure.
"One of the core components of that new project, inspired by this work, will be an investigation of fluids circulating at lower temperatures beneath the seafloor of an ocean world like Europa," German said. "We will investigate how these fluids continue to release nutrients, synthesize organic molecules and, perhaps, even host primitive microbial life, just as they do here in Earth's deep oceans." This focus reflects growing recognition that life can thrive in a wide range of hydrothermal environments, not only at the hottest and most visually dramatic vents.
The team also looks ahead to the arrival of NASA's Europa Clipper mission, which is scheduled to begin flybys of Europa in 2031. "This is an exciting time to be starting the next stage of our investigations," German said. "By 2031, when the Europa Clipper begins flybys of that moon, we plan to have much more information available to help interpret the precise measurements of its ice caps and oceans that the spacecraft will make. We plan to be ready." By integrating modeling, terrestrial analog studies, and mission planning, researchers hope to turn Europa's quiet seafloor from a challenge into an opportunity for understanding how life might emerge and persist on ocean worlds across the solar system.
Research Report:Little to no active faulting likely at Europa's seafloor today
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