In four years, National Aeronautics and Space Administration (NASA)’s Europa Clipper mission will arrive in Jupiter’s orbit to investigate whether the planet’s icy moon, Europa, could support life. In the interim, researchers like Sven Simon, a professor in the Schools of Earth and Atmospheric Sciences and Physics, are working to uncover critical information to support the rapid analysis of measurements from the mission.

Simon’s research team has been awarded $1.4 million through NASA’s Precursor Science Investigations for Europa (PSI-E) program. Their project is one of seven selected to provide essential insights that, according to the program announcement, “will maximize the science return during the radiation-limited lifetime of the Europa Clipper.” 

Simon also serves as the institutional lead co-investigator of a second $1.4 million project, led by researchers at the University of California, Berkeley, which seeks to decipher how Europa's atmosphere and ionosphere contribute to the magnetic field near the moon. This project was selected during the same call for proposals.

“The research award is a fantastic opportunity to contribute to a mission centered on Europa’s complex plasma and electromagnetic environment,” says Simon, referencing the Georgia-Tech led proposal. “Our project combines foundational plasma physics from our School of Physics and geophysical knowledge from our School of Earth and Atmospheric Sciences to understand how the magnetic field near Europa is affected by the plasma populating Jupiter’s environment.”

The research team includes Earth and Atmospheric Sciences Ph.D. students Ariel Tello Fallau and Charles Michael Haynes. Neil Baker, a Ph.D. student in the School of Physics, is contributing to the Berkeley-led PSI-E project that also includes Georgia Tech alumnus Lucas Liuzzo (Ph.D. EAS 2018), now an assistant research scientist at the University of California, Berkeley’s Space Sciences Laboratory. 

Groundwork for discovery

With a radius of only 1,560 kilometers, Europa is one of Jupiter’s four largest moons, known as the Galilean moons, discovered by Italian astronomer Galileo Galilei in the 1600s.

More than two decades ago, data from NASA’s Galileo mission — specifically magnetic field measurements collected far above Europa’s surface — pointed to the existence of a global subsurface ocean. This ocean, which may contain more liquid water than all of the Earth’s oceans combined, has made Europa a prime candidate in the search for life beyond Planet Earth.

“Finding evidence of a saltwater ocean lurking beneath Europa’s surface was a serendipitous discovery during the Galileo mission,” Simon explains. “NASA’s Europa Clipper mission picks up where the Galileo mission left off.” 

Launched in October 2024, the Europa Clipper space probe is expected to reach Jupiter’s orbit in 2030. That gives Simon and his team only a few years to complete their analysis. 

“Our research is doing the preparatory work to determine what and where we can measure further magnetic evidence of the ocean beneath Europa’s surface,” says Simon. “When the spacecraft arrives, we will find out whether our predictions are correct.”

Using advanced computer simulations, the team aims to better understand the magnetic fields near Europa. Part of these fields is generated by electric currents in the moon’s saltwater ocean; the other part is created by fast-moving flows of plasma — ionized matter that fills much of space — as it interacts with Europa’s atmosphere and surface.  

“Our project focuses on how the magnetic fields from plasma flow patterns compete with the magnetic signal from Europa’s ocean,” says Simon. “We want to determine which part of the magnetic field near Europa originates from the ocean and which part is a disruptive effect from the plasma.”

Deciphering these magnetic signals will provide essential context for interpreting Europa Clipper’s measurements, helping to not only confirm the ocean’s existence but also reveal details about its structure.