Click for originial image.

Past cool images on Behind the Black showing endless dune fields on Mars have generally focused on two places, the giant Medusae Fossae Formation volcanic ash deposits in the dry equatorial regions of Mars and the Olympia Undae dune sea that surrounds the Martian north pole.

Today’s image to the right, rotated, cropped, reduced, and sharpened to post here, takes us to a completely different dune sea. Taken on February 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), the picture also shows an endless dune sea, though there is faint evidence on those dune fields of buried features, such as the meandering east-west feature in the picture’s center.

This dune sea is also in the dry equatorial regions, like Medusae, but it is much farther east, and sits surrounded by Mars’ biggest volcanoes.

The white dot south of Olympus Mons and west of the three other great volcanoes marks the location of this picture. The white box outlines the whole dune field itself, which is about 100 miles long its greatest cross section.

A MRO context camera image taken on January 3, 2010 covers about two-thirds of this entire dune field, revealing its almost level nature. Except for the dunes, the terrain here is almost as flat as a tabletop. That flatness suggests strongly that we are looking at a lava flood plain which had poured out from one of the nearby giant volcanoes, or from the large fissure vents to the southwest and and northeast.

The sand dune sea was probably deposited later, and is likely made up of volcanic ash from those eruptions, or volcanic dust eroded off the lava by wind over the eons. Whether those dunes are now solid and unmoving, or still made of dust that are shifted over time by the wind, is probably the main scientific question that needs answering. Since this however is the first high resolution image taken of this entire dune field, that question cannot yet be answered, because we don’t yet have comparison images over time.