Astronomy Picture of the Day . Mercury's Faults . ... Credit: NASA , JPL , Mariner 10 , Calvin J. Hamilton ( LANL ) Explanation: The surface of the planet Mercury is not without fault. In this case, however, "fault" refers to unusual surface features that are the topic of much speculation. ... Such rupes probably originate from large impacts and a general shrinking of Mercury 's crust, which in turn causes parts of the crust to push above other parts. ... Publications with keywords: Mercury . ...