A very thin hydrogen atmosphere was created and blown away by solar wind, but it retains a thin ozone layer detected by the Hubble Space Telescope.  
Kittu is one of the rare dark ray craters that are found mostly on this satellite.  A very thin hydrogen atmosphere was created and blown away by solar wind, but it retains a thin ozone layer detected by the Hubble Space Telescope.  It has been found to possess its own magnetosphere field embedded inside its planet's larger one and also possesses a massive dark, oval-shaped mass called Galileo Regio.  FTP, name this satellite similar in size and density to neighboring Callisto, the largest moon of Jupiter, and the largest moon in the solar system.
Kittu is one of the rare dark ray craters that are found mostly on this satellite.  
Ganymede