Juno is a nasa Jupiter orbiter launched in 2011 as part of the New Frontiers Program, managed by nasa-jpl. Its principal investigator is scott-bolton of the southwest-research-institute.
Europa Science
Juno’s Microwave Radiometer (MWR), originally designed for Jupiter atmospheric study, was repurposed for icy-moon science. During a September 29, 2022 flyby within ~360 km of europa, the MWR produced the first measurement discriminating between thin- and thick-shell models of Europa’s ice crust, estimating the conductive ice shell at ~29 km thick. This result was published in Nature Astronomy (Dec 17, 2025).
Relevance
The Europa ice-shell measurement provides critical pre-arrival context for europa-clipper (arriving 2030) and juice (arriving 2031), informing habitability assessments for ocean-worlds astrobiology.