This composite image shows suspected plumes of water vapor erupting at the 7 o’clock position off the limb of Jupiter’s moon Europa. The Hubble data were taken on January 2014, and appear to show plumes that spit out as much as 125 miles. The image of Europa, superimposed on the Hubble data, is assembled from data from the Galileo and Voyager missions. (NASA/ESA/W. Sparks (STScI)/USGS Astrogeology Science Center)
Europa is a moon no bigger than our own and is covered by deep layers of icer, but it brings with it a world of promise. Science fiction master and sometimes space visionary Arthur C. Clarke, after all, named it as the most likely spot in our solar system to harbor life, and wrote a “2001: A Space Odyssey” follow-up based in part on that premise.
Many in the planetary science and astrobiology communities are similarly inclined and have supported a specifically Europa mission geared to learning more about what is generally considered to be a large ocean beneath that ice.
Along the way, Europa became the only object deemed by Congress to be an obligatory NASA destination, and formal plans for such a voyage have been under way — however slowly ...