Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on September 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small section of the Cerberus Fossae cracks, a parallel series of cracks that stretch more than 700 miles across the volcanic plains of Mars.

These cracks formed when the ground spread apart, creating a void in which the surface collapsed. You can see this process illustrated quite clearly by the crater in the lower right, as indicated by the arrow. The crater had existed prior to the crack. When the ground split and collapsed, only the northeast quadrant of the crater was destroyed.

These cracks might also have been the source of Mars’ most recent large volcanic event, as shown by the overview map below.

The white dot inside the rectangle on the overview map to the right marks the location, also indicated by the small box inside the inset. The Cerberus Fossae cracks run east to west, and cut across what the seismometer on the lander InSight found to the most quake-prone region of Mars. It appears that when these cracks opened they might have been the source of the Athabasca Valles flood lava event, thought to have occurred about 600 million years ago when it covered an area about the size of Great Britain in only a matter of weeks. The lava flowed to the southwest, almost at perfect right angles to Cerberus Fossae. The flood then divided, with some heading to the south and the majority flowing west.

If Cerberus Fossae is the source of this flood, it suggests the ground cracked 600 million years ago as well. Why it cracked is less clear, though it likely had something to do with underground volcanic activity that pushed the Athabasca lava upward and out, forcing the surface to stretch and split.