The Jupiter moon Europa is about to get a lot more interesting. Not only is the moon a candidate for potentially hosting life, but now, it could also have its own plate tectonics that move and shift its surface.
A new study of Europa shows evidence of these plate tectonics. If correct, that would make Europa the only other body in our solar system, other than Earth, to have a surface shaped in such a way.
The Earth's outer shell is full of dozens of plates. Throughout Earth's history, these plates shift and move, creating mountains and mountain ranges, volcanoes and deep ocean trenches. Shifting of the plates often triggers earthquakes, such as the San Andreas fault in California.
Astronomers now believe that Europa's outer shell moves in similar ways. Researchers carefully studied photos from NASA's Galileo Mission, which orbited Jupiter from 1995 through 2003. They viewed the images as one might a jigsaw puzzle, studying ridges and features that were separated by movements of Europa's crust. Once put together, though, the puzzle had a blank space. Scientists concluded that this empty space was the result of crustal movement that sucked it into Europa's interior, much like what happens on Earth.
"We see areas where cracks have opened and new material has come up from underneath the ice, creating new surface areas," says Dr. Simon Kattenhorn of the University of Idaho, lead author on the study. "And unless the moon is expanding, which we don't think is the case, you have to remove surface from somewhere else in order to accommodate the new surface area being created."
This is just one of many discoveries recently made about Europa. In December 2013, astronomers discovered water vapor plumes on the moon's surface. Most scientists also believe that Europa may sustain life beneath its top icy layer, where they believe numerous oceans exist.
However, Europa still isn't a priority for exploration by agencies, such as NASA. Although the Jet Propulsion Laboratory is working on a Europa-related mission, the budget for the mission was recently cut from $2 billion to just $1 billion. The agency is, however, looking over suggestions for the mission, but there is still no guarantee that it will fly with such a low budget.
"It's really frustrating to talk about $1 billion concepts as if researchers hadn't already considered that," says Britney Schmidt, a planetary scientist at the Georgia Institute of Technology in Atlanta. "If you want to do the best science out there, totally committed to by the community, this is the mission you send."