Europa is Jupiter’s fourth largest moon which is slightly smaller than the
Earth’s Moon. Europa is believed to be composed of silicate rocks with a
layer of water ice covering the entire surface.
This image was created by recent discoveries on Europa of regions that
look very much like pack-ice on Earth’s polar seas during spring thaws.
This view is from an altitude of several thousand feet.
It is thought that beneath Europa’s surface ice there is a layer of liquid
water, perhaps as much as 30 miles deep. This subsurface “ocean” would
be kept liquid by tidally generated heat. If Europa does indeed harbor a
liquid water ocean, it would be the only place in the Solar System besides
Earth where liquid water exists in significant quantities. It may also be the
only place in the Solar System where life has evolved outside the Earth.
For an interesting YouTube Video of how we might
explore Europa click Here