- Europa's salty ice near the surface may drip into its subsurface ocean transporting chemicals
- This process, called lithospheric foundering, is similar to Earth's crust sinking into the mantle
- Models show ice erosion could deliver surface material to the ocean in 30,000 to 10 million years
Jupiter's icy moon Europa may have a previously overlooked way of delivering life-supporting chemicals to its vast subsurface ocean, according to new research. Scientists have long been intrigued by Europa because its hidden global ocean beneath a fractured, frozen surface may contain twice as much salty water as all of Earth's oceans combined. Unlike Earth, however, Europa's ocean lacks oxygen and sunlight, meaning any potential life there would rely on chemical energy instead of photosynthesis. A key question has been how ingredients for this energy, such as oxidants formed on the surface by Jupiter's intense radiation, could reach the ocean below, reported the Space.com.
A new study by researchers at Washington State University suggests that a slow but persistent geological process may be transporting chemicals formed on Europa's surface to its underlying ocean. Using computer models, the research team found that patches of salt-rich ice near Europa's surface may be denser and mechanically weaker than the surrounding pure ice. Under suitable conditions, these dense ice layers could break apart and slowly "drip" through the thicker ice layer, reaching the ocean.
The study calls this process lithospheric foundering, similar to a process on Earth in which parts of a planet's outer crust sink into the mantle. In 2025, scientists observed such activity beneath the Sierra Nevada Mountains in California.
Researchers modeled Europa's approximately 30-kilometer-thick ice layer and tested it under six different conditions. In all cases, the top 300 meters of surface ice gradually eroded toward the base of the crust. In some simulations, this process began in 1 to 3 million years and reached the ocean in 5 to 10 million years. However, in more damaged or weakened ice layers, this process could begin in as little as 30,000 years. The researchers said this is possible for almost any salt content, as long as there is some weakness in the ice.
According to the study, this process "could be an effective way to transport surface material to the ocean beneath Europa."
NASA's Europa Clipper mission, launched in 2024, will study Europa in more detail. This spacecraft will arrive in the Jupiter system in April 2030 and fly by Europa approximately 50 times over four years. These missions will allow scientists to measure ocean depths and further evaluate the Moon's habitability.
The study was published in "The Planetary Science Journal" on January 20.
