Numerous small mounds having summit craters are found in various locutions on Mars. The mounds shown here are east of the Hellas basin. These features have been interpreted to be pseudocraters created by localized phreatic (steam-related) explosions where lava interacts with volatile-rich ground. However, images presently available do not have sufficient resolution to show conclusive evidence of a volcanic origin for the mounds.
43 S, 239 W;
portion of Viking Orbiter frame 586B34, high-pass spatially filtered version.