Europa, which is slightly smaller than Earth's moon, has an extremely smooth surface with a broken eggshell-like solid ice cap. There is a huge ocean in the interior with more water than on Earth. It's possible that it could support life as we know it. The presence of permanent water vapour in Europa's tenuous atmosphere has been discovered through Hubble Space Telescope scans. Water vapour is regularly regenerated throughout one hemisphere of the moon, according to Hubble observations from 1999 to 2015.
Europa's brilliant white and bluish surface is largely made up of water ice, with only a few non-ice components. Long, black lines in the crust are fractures, some of which are over 1,850 kilometres long. On Sept. 21, 2003, the Galileo mission came to an end when the spacecraft was ordered to drop into Jupiter's atmosphere, where it was destroyed. Scientists are still studying the data is collected to this day.
However, fresh Hubble images from 1999 to 2015 reveal similar levels of water vapour dispersed across a broader area of Europa. This points to a process is associated with a water vapour atmosphere on Europa's leading hemisphere, which is always in the opposite direction of the moon's orbital motion. It's unclear what causes this disparity between the following and trailing hemispheres.