Apparently something to do with evidence of a subsurface ocean there. Teleconference scheduled for next Monday. http://www.nasa.gov/press-release/n...-on-evidence-of-surprising-activity-on-europa
Many observations of Europa have observed over time, a changing of the landscape and particularly the apparent "cracks" that criss cross Europa's surface, leading to the hypothesis that the Ocen that probably lies beneath, is causing the upheaval.