Europa's Icy Plate Tectonics May Support Life

Scientists have found evidence of icy plate tectonics on Jupiter's moon Europa, suggesting that this far-away celestial body could support life, according to new research.

The research team found clear evidence that Europa's icy crust was expanding; however, they couldn't determine how the old crust was being destroyed to make way for the new crust. Until now, scientists had believed that Earth was the only world that possessed this type of surface-shifting geological activity.

"From a purely science or geological perspective, this is incredible," study lead author Simon Kattenhorn of the University of Idaho told Space.com. "Earth may not be alone. There may be another body out there that has plate tectonics. And not only that, it's ice!"

Plate tectonics is the scientific theory that Earth's outer layer is made up of plates or blocks that move, which accounts for why mountain and volcanoes form and earthquakes happen.

Kattenhorn and co-author Louise Prokter, of Johns Hopkins University's Applied Physics Laboratory, studied photos of Europa taken by NASA's Galileo spacecraft, which orbited Jupiter from 1995 until 2003. They reconstructed the images, and were surprised to find that an area more than 12,000 square miles (nearly 20,000 square kilometers) was actually missing.

Their findings also suggest that this missing puzzle piece moved under a second surface plate - a scenario commonly seen on Earth at plate-tectonic boundaries. Kattenhorn and company believe that this terrain was pushed into the interior rather than crumpled up as the two plates mashed against each other.

"Europa may be more Earth-like than we imagined, if it has a global plate tectonic system," Kattenhorn said in a NASA news release. "Not only does this discovery make it one of the most geologically interesting bodies in the solar system, it also implies two-way communication between the exterior and interior - a way to move material from the surface into the ocean - a process which has significant implications for Europa's potential as a habitable world.

If the team's results - published in the journal Nature Geoscience - are correct, it could mean re-writing the planetary textbooks.