Overview
- NASA reports that Juno’s Microwave Radiometer measured an average ice thickness of roughly 18 miles in the region sampled during a close 2022 flyby.
- The data provide the first clear resolution of competing thin-versus-thick shell models for Europa’s outer ice layer.
- MWR detected near-surface “scatterers” just inches across that extend hundreds of feet deep, features judged unlikely to transport oxygen or nutrients to the ocean below.
- The estimate pertains to the cold, rigid outer layer; a deeper convective layer would increase total thickness, while dissolved salts could reduce the estimate by about 3 miles.
- Results inform mission planning as Europa Clipper and ESA’s JUICE head for the Jovian system, with Juno set for its 81st Jupiter flyby on Feb. 25, 2026.