Its massive solar panels make Clipper the biggest craft built by NASA to investigate another planet or another moon of a planet. The mission will take 5 and half years to reach Jupiter and will sneak within 25 kilometers of Europa’s surface — considerably closer than any other spacecraft until now. Euripa is one of Jupiter’s 95 known moons and is almost the size of our own moon, so studying will be interesting: the moon is encased in an ice sheet estimated to be 15 kilometers to 24 kilometers thick and scientists believe this frozen crust hides an ocean that could be 120 kilometers or more deep. The Hubble Space Telescope has spotted what appear to be geysers erupting from the surface.
