
Europa Plume Claims Doubted: Hydrogen Exosphere, Not Local Water Vapor
A new reanalysis of Hubble data reduces the 2014 claim of 200-km-high water-vapor plumes on Europa from 99.9% confidence to under 90%, suggesting the earlier signal may be statistical noise; meanwhile there’s evidence for a persistent hydrogen exosphere but no localized water vapor. Future missions like Europa Clipper and JUICE will help settle the question.



