Evidence of plate tectonics, which is the first sign of this type of surface-shifting geological activity on a world other than Earth, have been found on Jupiter's moon Europa.
While examining Europa images taken by NASA's Galileo orbiter in the early 2000s, researchers found clear visual evidence of Europa's icy crust expanding, however, despite the degree of extension evident on Europa's surface, Louise Prockter, of the Johns Hopkins University Applied Physics Laboratory in Laurel said that its still unknown how it was accommodated.
Europa is one of Jupiter's four largest moons and slightly smaller than Earth's moon, where surface blocks are known to have shifted in the same way blocks of Earth's outer ground layer on either side of the San Andreas fault move past each in California.
The scientists studying Europa while rearranged the icy terrain in the images found more than 12,000 square miles of the surface were missing in the moon's high northern latitudes and further evidence suggested that the missing terrain moved under a second surface plate, which is commonly seen on Earth at plate-tectonic boundaries.
Curt Niebur, Outer Planets program scientist at NASA Headquarters had previously said that studying Europa addresses fundamental questions about this potentially habitable icy moon and the search for life beyond Earth.
The results appear in the online edition of the journal Nature Geoscience.