Caloris Basin has knobs

While most of our planet-exploring attention is focused on the exploits of the Mars rovers, it's worth remembering that the amazing MESSENGER is still studying Mercury.

Here's a recent reminder:

CAPTION: The plains that surround the Caloris basin are geologically complex. Today's featured images highlights some of the kilometer-scale knobs that surround much of the basin, which are thought to be blocks of material ejected by the Caloris basin-forming event. This area, a region within Tir Planitia, has also been subjected to compressional stresses, which resulted in the formation of scarps that cut across the scene. Unraveling the complex sequence of events in this region, which includes deposition of ejecta, possible volcanic resurfacing, and tectonic deformation, will be aided by the high-resolution targeted images to be collected in MESSENGER's second extended mission.