Researchers analyzed data from NASA/ESA’s Hubble Space Telescope and found the first evidence of the presence of water vapor in the atmosphere of Jupiter’s largest moon, Ganymede. Previous research has shown that Ganymede might be having more water than Earth, but because the temperatures are very low there (minus 100 to 180 degrees Celsius), surface water may freeze. It has been suggested that the water may be around 160 kilometers below the surface. New evidence of a water atmosphere on Ganymede is vital to our search for extraterrestrial life and an inhabited world.
In 1998, the Hubble Space Telescope Imaging Spectrograph (STIS) recorded the first ultraviolet image of Ganymede. When examining the emissions, the researchers discovered that Ganymede has a constant magnetic field and some atomic oxygen. In 2018, the Hubble’s Cosmic Origin Spectrograph (COS) was used to measure the content of this atomic oxygen. The research team summarized the data for 1998, 2010, and 2018, and to their surprise, they found some differences from the original results.
“Only O2 was observed at first,” explains Lorenz Roth of KTH Royal Technical University in Stockholm, Sweden. “The water vapor we are measuring now comes from ice sublimation, which is caused by the heat release of H2O vapor in the warm ice zone.” It was published yesterday in the journal Natural Astronomy. The author explains that at noon, the surface of Ganymede will heat up near the equator and the ice will release water molecules.
The European Space Agency (ESA) is preparing for the Jupiter Icy Moon Explorer (JUICE) mission, this new discovery adds to the fun. The JUICE mission will begin next year and will reach Jupiter in 2029. This will spend 3 years exploring its three largest moons. “Our results can be used by the JUICE tool team to provide valuable information that they can use to refine their observation plans to optimize the use of spacecraft,” Roth added.
“Understanding the Jupiter system and reveal its history, from its origins to its possible creation of habitability. The environment will enable us to better understand how giant planets and their moons form and evolve. In addition, we hope to have a new understanding of the possibility of life formation in exoplanet systems such as Jupiter,” the ESA statement added.