The first evidence of water vapor in the atmosphere of Jupiter’s moon Ganymede, the Solar System’s largest moon, has been discovered by astronomers. They believe Ganymede could hold more water than the world’s oceans combined. However, liquid water is difficult to come by. According to the European Space Agency, the temperatures are so cold that all of the water on the surface has frozen solid, and the ocean is about 100 miles (160 kilometres) beneath the crust. Nonetheless, scientists believe that finding water is an important first step in determining whether or not life could exist on a celestial body. The astronomers used Hubble Telescope archival datasets from the past two decades to come up with their findings.
The European Space Agency (ESA) stated that finding liquid water on other planets is critical to determining whether they are habitable. The study is based on data from Hubble’s first ultraviolet (UV) images of Ganymede, which he took in 1998. These images revealed a particular pattern in the observed emissions from the moon’s atmosphere which was somewhat similar to those observed on Earth and other planets with magnetic fields.
Ganymede’s surface temperature varies dramatically throughout the day, according to scientists. Around noon, the temperature may rise to the point where the icy surface releases small amounts of water molecules. It’s unlikely that the vapor came from the oceans, which are miles below the crust.
‘Initially, only the O2 (molecular oxygen) had been observed,’ said lead researcher Lorenz Roth, adding that this is produced when charged particles erode the ice surface.
He said the water vapor his team has found originates from ice sublimation.