Hubble Telescope Finds Evidence of Water Vapour on Ganymede

Astronomers from the Hubble Telescope have found evidence of water vapour on Ganymede which is the largest moon in of our solar system. Ganymede’s ocean resides roughly 160 kms below the crust. Astronomers detected the evidence of water vapour.Ganymede’s atmosphere using the latest and historical datasets.

According to a study, water vapour forms when ice on the moon turns from solid to gas. Previous studies state there the Jupiter’s moon contains more water than that on Earth. However, the temperature there is extremely cold which has frozen the ice solid, says NASA.

Astronomers, re-observed the data collected by the Hubble Space Telescope from last two decades to see find the evidence of water vapour.In 1998, the Imaging Spectrograph of the telescope captured first ultraviolet (UV) images of Ganymede. It also revealed a magnetic field but was comparatively weak. Similarly, the UV observations also revealed molecular oxygen (O2). However, some features of the emissions did not match the O2 on Earth. But, scientists concluded that it is likely to contain higher concentrations of Oxygen (O).

According to studies, the researchers say, temperature on the surface the Ganymede varies throughout the day. The temperature around noon near the equator also varies that may make the surface warm. This allows the ice to release some water molecule, the researchers said.  The water vapors observed by the astronomers are formed as a result of ice sublimation caused due to thermal escape of water vapour.