NASA’s Hubble Space Telescope has provided new datasets and historical data that have helped astronomers discover the first evidence of water vapor in Jupiter’s atmosphere.
According to a Monday study in Nature Astronomy, water vapor is formed when the moon’s ice turns from solid to liquid.
NASA stated that previous studies provided evidence that Ganymede is the largest moon in our solar system and contains more water than any of Earth’s oceans.
According to the US space agency, the temperatures are so low that water on the surface freezes solid.
Ganymede’s ocean would be located approximately 160 km below the crust. Therefore, water vapor wouldn’t represent the ocean’s evaporation.
Hubble observations over the past two decades were reexamined by astronomers to discover evidence of water vapor.
Hubble’s Space Telescope Imaging Spectrograph captured the first ultraviolet (UV), images of Ganymede in 1998. It revealed bright ribbons of electrified gases called auroral bands and further evidence that Ganymede is subject to a weak magnetic field.
These UV observations have many similarities. This is due to the presence of molecular oxygen (O2).
However, there were some features that did not match those expected to be produced by pure O2 atmospheric.
Scientists also concluded that this discrepancy could be due to higher levels of atomic oxygen (O).
The team that measured the amount of atomic oxygen using Hubble was led by Lorenz Roth, KTH Royal Institute of Technology, Stockholm.
The analysis was a combination of data from Hubble’s Cosmic Origins Spectrograph 2018 and archive images from Space Telescope Imaging Spectrographs (STIs) 1998 to 2010.
Contrary to their original interpretation of 1998’s data, they found that there was very little atomic oxygen in Ganymede’s atmosphere.
Roth and his team looked at the relative distributions of the aurora in UV images.
The surface temperature of Ganymede varies greatly throughout the day. At noon, near the Equator, it might become sufficiently warm to release small amounts of water molecules.
They said that the perceived differences in UV images were directly related to where water is expected to be found in the moon’s atmosphere.
This finding increases anticipation for the European Space Agency’s (ESA) upcoming mission Jupiter Icy Moons Explorer (JUICE).