It’s small, it’s hot, and it’s shrinking. New research suggests that Mercury is contracting even today, joining Earth as a tectonically active planet.
Images obtained by NASA reveal previously undetected small fault scarps— cliff-like landforms that resemble stair steps. These scarps are small enough that scientists believe they must be geologically young, which means Mercury is still contracting and that Earth is not the only tectonically active planet in our solar system, as previously thought.
Managed by the Johns Hopkins University in Laurel, Maryland, MESSENGER launched Aug. 3, 2004 and began orbiting Mercury March 18, 2011. The mission ended with a planned impact on the surface of Mercury on April 30, 2015.
Editor: Sarah Loff