William Sparks and colleagues (including Melissa McGrath of The SETI Institute, no relation so far as I know) published a study using the Hubble Space Telescope to detect evidence of water plumes shooting out from Europa .
Such plumes of water have been observed at Saturn’s moon Enceladus, and there is strong reason to think that Europa has a liquid water ocean under the frozen surface. So this would not be unbelievable.
The new study stretches the limits of the Hubble, identifying smudges that could be water plumes. Other spectroscopic studies have detected Hydrogen and Oxygen in these regions, supporting the notion that there might be water there. Suggestive, but hardly conclusive or very detailed evidence.
The possibility of water plumes high above the surface is particularly interesting because Europa’s ocean is one of the places in our solar system that might support life. A mission to that ocean will be really, really difficult, but maybe we can orbit or land on the surface to sample from these plumes. This could tell us quite a bit about what is down below, even if we can’t visit yet.
Both NASA an ESA are planning possible missions to fly by Europa in the next decade. Clearly, investigating water jets, if they can be found, will be a high priority.
- W. B. Sparks, K. P. Hand, M. A. McGrath, E. Bergeron, M. Cracraft, and S. E. Deustua, Probing for Evidence of Plumes on Europa with HST/STIS. The Astrophysical Journal, 829 (2):121, 2016. http://stacks.iop.org/0004-637X/829/i=2/a=121