Europa from Juno (Credits: Image data: NASA/JPL-Caltech/SwRI/MSSS; Image processing: Björn Jónsson)

Jupiter�s moon Europa was captured by the JunoCam Instrument aboard NASA�s Juno Spacecraft during the Mission�s close flyby on Sept. 29, 2022. Data from NASA�s Juno mission has provided new insights into the thickness and subsurface structure of the icy shell encasing Jupiter�s moon Europa. Using the spacecraft�s Microwave Radiometer (MWR), mission scientists determined that the shell averages about 18 miles (29 kilometers) thick in the region observed during Juno�s 2022 flyby of Europa. The Juno measurement is the first to discriminate between thin and thick shell models that have suggested the ice shell is anywhere from less than half a mile to tens of miles thick.

Slightly smaller than Earth�s moon, Europa is one of the solar system�s highest-priority science targets for investigating habitability. Evidence suggests that the ingredients for life may exist in the saltwater ocean that lies beneath its ice shell. Uncovering a variety of characteristics of the ice shell, including its thickness, provides crucial pieces of the puzzle for understanding the moon�s internal workings and the potential for the existence of a habitable environment.