Astronomers have used archival datasets from the NASA/ESA Hubble Space Telescope to reveal the first evidence for water vapor in the atmosphere of Jupiter’s moon Ganymede, the result of the thermal escape of water vapor from the moon’s icy surface. Jupiter’s moon Ganymede is the largest moon — and the ninth-largest object — in the … Continue reading First Evidence of Water Vapor at Jupiter’s Moon Ganymede – May Hold More Water Than All of Earth’s Oceans