THE WOODLANDS, TEXAS—With a saltwater ocean hiding under an icy shell, Jupiter’s moon Europa is one of the most promising places in the Solar System to look for life. Later this year, NASA will launch a $5 billion mission, Europa Clipper, to study the ocean and perhaps even sample it—assuming the moon ejects plumes of water through cracks in the ice, as some research has suggested.

But two modeling studies presented yesterday here at the Lunar and Planetary Science Conference suggest Europa’s rocky interior may be geologically dead. Magma may be unable to penetrate the sea floor to create the hydrothermal vents that on Earth are thought to have been a haven for early life, and the moon’s rocky crust seems to resist seismic fracturing. Without that mix of heat and fresh rock to drive geochemical reactions in the ocean, Europa may be unlikely to foster conditions conducive to life.

It’s a “depressing parade” of conclusions, said one presenter, Austin Green, a planetary scientist at NASA’s Jet Propulsion Laboratory. “If this volcanism is necessary for habitability, Europa’s ocean is uninhabitable.”