Not too long ago, astronomers determined that Saturn's moon, Enceladus, actually harbored a large ocean beneath an icy layer. The analysis came from studying how the moon apparently wobbled, from various gravitational effects, in a way that indicated a liquid interior. Further analysis determined this ocean is likely salty with mixtures of NaCl and Na2CO3. It so happens that Enceladus' ice layer is fissured on the southern pole with jets of ocean spray spewing forth. NASA redirected the Cassini spacecraft to "fly within 30 miles of the moon through the spray":http://phys.org/news/2015-10-nasa-spacecraft-plunges-saturn-moon.html in order to collect samples. Researchers hope the data will provide evidence indicating the possibility of life.