Cascading dunes in a martian crater
A new mosaic from ESA’s Mars Express shows a swirling field of dark dunes cascading into sunken pits within a large impact crater.
ARCHIVE CONTENT
05 OCT. 2017
publication date
1059
Views
Dunes are prominent indicators of prevailing winds, as can be seen on this crater floor on Mars, imaged by ESA’s Mars Express on 16 May.
Media modal
Dune field in a crater, plan view
Depressions such as impact craters can act as traps for sediments that have been blown in from elsewhere, accumulating in various patterns whipped up by strong winds.
The dune field in this unnamed 48 km-wide impact crater in the southern highlands of Mars includes sickle-shaped dunes known as barchans, and parallel ridges of dunes called transverse dunes.
A smoothly distributed sand sheet stretches between the dunes and the western wall of the crater.
Media modal
Dune-filled crater in context
Barchans are the most common dune type found on Mars, and are also prevalent in Earth’s deserts. The shallower slope faces the wind, with the steeper, curved slope downwind, the ‘horns’ of the individual dunes pointing in the direction the wind is blowing. In this example, a southeasterly wind at the time of dune formation can be assumed.
Many nearby craters in this region also host dunes, and show a northwest shift of their dune fields relative to the crater centre, arguing for a uniform wind direction from the southeast.
Media modal
Dune-filled crater topography
To the south of the dune field in the large crater, a single elongated transverse dune extends beyond the main field for several kilometres. Perhaps the underlying topography combined with near-surface winds caused the sediments to pile up here, or over time the smaller barchan dunes joined together.
Media modal
Dune-filled crater in 3D
This scene is situated south of Tharsis, the largest volcanic province on Mars and home to Olympus Mons. Past volcanic activity in Tharsis produced vast amounts of basalt, fine pyroclastic deposits and ash, which were likely swept across the region to provide a source for the dark dune material observed in these craters today.
Media modal
Winter in Argyre
Over billions of years, the southern uplands of Mars have been pockmarked by numerous impact features, which are often so closely packed that they overlap. One such feature is Hooke crater, shown in this frost-tinged scene, imaged by ESA’s Mars Express during winter in the southern hemisphere.
Media modal
Related links
Mars Express overview
Mars Express science highlights
Mars Express has provided an unprecedented breadth and depth of information about Mars, from providing the most complete map of the chemical composition of the atmosphere, to tracing the history of water across the globe.
Mars Express in-depth
Share this page
stay updated
Subscribe to our newsletter to receive the latest news, mission updates, and exclusive insights directly in your inbox. Be the first to know about our upcoming projects and breakthroughs.