Question #51 – What is so interesting about Jupiter's moon Europa?
Europa is the smallest of Jupiter's Galilean moons, but it is not small! It is the sixth largest moon in the solar system. Scientists believe that there is a salty ocean beneath Europa's icy crust. While Europa is much smaller than Earth, its ocean may contain twice the water that is on Earth. In 2012, the Hubble Space Telescope observed a plume of water jetting from Europa's south polar region. Since then, more apparent plumes have been seen. The presence of water beneath Europas's frozen surface leads scientists to believe some form of life could exist there.
See NASA's Solar System Exploration page about Europa for more information.
Europa, photographed by the Galileo spacecraft in 1996. Astronomy Picture of the Day, September 27, 2016
Image Credit: Galileo Project, JPL, NASA