There are many knob formations is the southeastern Acidalia region of Mars. All show a hilltop crest except one which has a summit crater that resembles a cone volcano in this image captured by NASA Mars Reconnaissance Orbiter.
There are many knob formations is the southeastern Acidalia region of Mars. All show a hilltop crest except one which has a summit crater that resembles a cone volcano in this image captured by NASA Mars Reconnaissance Orbiter.