Colorful Layered Rocky Outcrop on Mars (Photo)

This image shows part of Ladon Vallis, a long outflow channel on Mars. It was taken by the High Resolution Imaging Science Experiment (HiRISE), a camera onboard NASA’s Mars Reconnaissance Orbiter (MRO).

The Martian outflow channels are large topographical systems scoured out by ancient fluid flow from the sub-surface with the biggest ones extending for thousands of kilometers in length. Most scientists agree that the erosive force was water, although there are a few who believe it could have been lava, glaciers, or debris flows.

Ladon Vallis is about 600 kilometers (370 miles) long, and forms part of a larger system starting in Argyre basin to the south and spreading north through the Southern Highlands towards the larger Ares Vallis outflow system.

Here we are looking at part of Ladon Vallis in Ladon basin. The lightly colored deposits and layers above are quite different from the darker sediments distributed along the channel base with dunes partially covering impact craters and fractures in places.

The layers have built up from ponding of water and associated sediment as it traveled from Ladon Vallis into the basin.

Later flooding episodes from the basin to the north may have revealed and sculpted these older sedimentary layers.