It's All Mercury's Fault
This image, taken with the Wide Angle Camera (WAC), shows a portion of the Caloris Basin interior. The linear features visible in the left side of the image, running from top to bottom, are roughly concentric with the basin's rim. A second set of troughs (part of Pantheon Fossae) are radial to a point off the right side of the image. Both sets of troughs formed when the rocks of the basin interior experienced large horizontal forces that caused the surface to undergo faulting (fracturing) and to pull apart.
Date acquired: April 24, 2012
Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington