Mars deep down

August 19, 2014
Credit: ESA/DLR/FU Berlin

Scarring the southern highlands of Mars is one of the Solar System's largest impact basins: Hellas, with a diameter of 2300 km and a depth of over 7 km.

Hellas is thought to have formed between 3.8 and 4.1 billion years ago, when a large asteroid hit the surface of Mars. Since its formation, Hellas has been subject to modification by the action of wind, ice, water and volcanic activity.

Impact craters have also since pock-marked this vast basin floor, two of which are the focus of this image, taken by the High Resolution Stereo Camera on ESA's Mars Express on 17 December 2013. The ground resolution is about 15 metres per pixel.

These craters lie in the deepest, western portion of Hellas, and such a clear view is unusual because dust clouds typically obscure the basin floor. Indeed, this region seems to be covered by a thick blanket of dust.

The larger of the two craters is about 25 km across. A flow of material appears to have been transported from the top left of the scene and into the crater. Zooming in to the smooth mound and the area immediately around it reveals interesting textures that likely resulted from this flow.

Flow features are also seen outside of the craters, and in particular, at the centre left of the image near the top of the frame. Material also seems to have cascaded from the larger crater's rim and into a neighbouring smaller crater, at the far left of the image.

The morphology of many features in the Hellas Basin and its surroundings strongly suggests the presence of ice and glaciers.

For example, in the foreground and around the crater rim, polygons of patterned ground are visible which indicates the presence of water – this pattern occurs when fine grained and porous wet soil freezes.

Indeed, in the deepest parts of the basin, the atmospheric pressure is about 89% higher than at the surface, which may even offer conditions suitable for water. Radar images from NASA's Mars Reconnaissance Orbiter suggest that some craters in Hellas might contain water-ice glaciers several hundred metres thick, buried under layers of dust.

Explore further: Ice sculptures fill the deepest parts of Mars

Related Stories

Ice sculptures fill the deepest parts of Mars

April 3, 2012

One of the “weirdest and least understood” areas of Mars, the enormous Hellas Impact Basin contains strange flowing landforms that bespeak of some specialized and large-scale geologic process having taken place. ...

Mars: What lies beneath

August 13, 2013

There is much more to Mars than meets the eye. By using the radar on Mars Express, we can see several kilometres below the surface to see what lies beneath.

Cascading dunes in a Martian crater

May 16, 2014

A new mosaic from ESA's Mars Express shows a swirling field of dark dunes cascading into sunken pits within a large impact crater.

Forces of martian nature

July 11, 2014

The surface of Mars is pocked and scarred with giant impact craters and rocky ridges, as shown in this new image from ESA's Mars Express that borders the giant Hellas basin in the planet's southern hemisphere.The Hellas basin, ...

Recommended for you

Distant planet's interior chemistry may differ from our own

September 1, 2015

As astronomers continue finding new rocky planets around distant stars, high-pressure physicists are considering what the interiors of those planets might be like and how their chemistry could differ from that found on Earth. ...

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

Interstellar seeds could create oases of life

August 27, 2015

We only have one example of a planet with life: Earth. But within the next generation, it should become possible to detect signs of life on planets orbiting distant stars. If we find alien life, new questions will arise. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.