NASA detects water vapor on Jupiter's Ganymede — the largest moon in the solar system

NASA has detected water vapor for the very first time in the atmosphere of Ganymede — not only Jupiter's largest moon, but the largest moon in our entire solar system.

Researchers made the discovery using both new and archival data from NASA's Hubble Space Telescope, which is back in action after a computer anomaly suddenly shut down the 32-year-old system for a month. They published their findings this week in the journal Nature Astronomy.  According to NASA, the water vapor on Ganymede forms when ice from the moon's surface transitions from solid to gas, skipping the liquid state, also known as sublimation.