Click for original image.

Cool image time! The picture to the right, cropped, enhanced, and rotated so that north is to the top, was taken on May 30, 2026 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

This mound is small, only about 150 to 600 feet high, depending on where you mark the base. The science team labels the curved black arcs that cover the mound’s northern slopes as “small scale lobes,” suggesting they think these curves mark the foot of multiple small landslides, or more accurately described as “mass-wasting events,” as instead of an avalanche of discreet boulders and rocks, the slide is comprised of mud-like material sliding downhill en masse.

The black material at the foot of these slides as well as on the mound’s peak and south and eastern flanks is a bit more puzzling. The overview map below provides one possible explanation, but leaves us with other more tantalizing possibilities.

The white dot in the upper right marks the location, at about 75 degrees south latitude about 540 miles from the Martian south pole.

At this latitude orbital data has found ample evidence of near-surface ice. Similar black stains as seen here are often caused when the dry ice mantle that falls as snow in the high latitudes during winter sublimates into gas in the spring. The dry ice sublimates from the bottom up, with the gas bursting out at weak spots in the mantle, the gas pressure causing it to crack. With each burst the gas spreads such stains on adjacent ground. As it was spring at this location when the photo was taken, it is quite likely we are looking at such a process.

However, there is another possibility that must be considered, though unlikely. Orbital data has also found similar dark stains in the dry equatorial regions of Mars, in what I call volcano country because the dominant geological feature is flood lava that covers the surface for thousands of miles. Those stains however were not caused by CO2 sublimation. Located around fissures resembling volcanic vents, scientists instead think they are the evidence of a small volcanic event some 50,000 to 210,000 years ago.

Thus, it is also possible this mound is a small volcano, and the dark splotches and curves are evidence of vented lava from below.

Finally, the answer could actually be both. This mound might be a volcano, but instead of lava it is venting sublimated CO2 and water.