• Juno’s Microwave Radiometer measured Europa’s ice shell thickness at about 18 miles (29 km) during a 2022 flyby. • This is the first measurement distinguishing thin versus thick shell models, narrowing the range from sub‑mile to tens of miles. • Europa’s ice shell thickness informs scientists about subsurface ocean dynamics and potential habitability of its salty water. • Juno’s close flyby on September 29, 2022 captured high‑resolution images of fractures, ridges, and bands across Europa. • The data, published in Nature Astronomy on December 17, refines models of Europa’s internal structure. • Understanding the ice shell thickness is crucial for future missions targeting Europa’s ocean and assessing life‑supporting conditions.
Article Summaries:
- NASA’s Juno spacecraft, during a 2022 flyby of Jupiter’s moon Europa, used its Microwave Radiometer to measure the moon’s ice shell. The data indicate an average thickness of about 18 miles (29 km) for the outer, conductive layer, the first measurement that distinguishes between the previously proposed thin‑to‑thick shell models. If a warmer convective layer or dissolved salt exists, the total thickness could be larger or smaller by a few miles. The study, published Dec. 17 in Nature Astronomy, also found small surface‑level cracks and pores that extend only a few hundred feet, unlikely to provide a major conduit for nutrients to the subsurface ocean.
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