Image: Mars Express orbiter reveals overflowing craters

Feb 11, 2014
Credit: ESA/DLR/FU Berlin (G. Neukum)

(Phys.org) —Large and small, hundreds of thousands of craters scar the surface of Mars, hollowed out by a multitude of asteroids and comets that impacted the Red Planet throughout its history.

This image shows a region of the planet's known as Hephaestus Fossae – after the Greek god of fire – that was imaged by the high-resolution stereo camera on ESA's Mars Express orbiter on 28 December 2007. The image has been coloured to indicate the elevation of the terrain: green and yellow shades represent shallow ground, while blue and purple stand for deep depressions, down to about 4 km.

Scattered across the scene are a few dozen that cover a wide range of sizes, with the largest boasting a diameter of around 20 km.

The long and intricate canyon-like features that resemble riverbeds are the phenomenal aftermath of the same fierce impacts that created the largest craters.

When a small body such as a comet or an asteroid crashes at high speed into another object in the Solar System, the collision dramatically heats up the surface at the impact site.

In the case of the large crater seen in this image, the heat produced by such a powerful smash melted the soil – a mixture of rock, dust and also, hidden deep down, water ice – resulting in a massive overflow that flooded the surrounding environment. Before drying up, this muddy fluid carved a complex pattern of channels while making its way across the planet's surface.

The melted rock–ice mixture also gave rise to the fluidised appearance of the debris blankets surrounding the largest crater.

Based on the lack of similar structures near the small craters in this image, scientists believe that only the most powerful impacts – those responsible for forging the largest craters – were able to dig deep enough to release part of the frozen reservoir of water lying beneath the surface.

Explore further: Asteroid Steins in 3-D

Related Stories

Explosive crater twins on Mars

Apr 12, 2013

(Phys.org) —Dramatic underground explosions, perhaps involving ice, are responsible for the pits inside these two large martian impact craters, imaged by ESA's Mars Express on 4 January.

Asteroid Steins in 3-D

Sep 02, 2013

(Phys.org) —Five years ago this week, ESA's Rosetta mission flew by asteroid Steins en route to comet Churyumov–Gerasimenko, where it will finally arrive next year after a decade in space.

Nereidum Montes helps unlock Mars' glacial past

Nov 01, 2012

(Phys.org)—On 6 June, the high-resolution stereo camera on ESA's Mars Express revisited the Argyre basin as featured in our October release, but this time aiming at Nereidum Montes, some 380 km northeast ...

The scars of impacts on Mars

Mar 04, 2011

ESA's Mars Express has returned new images of an elongated impact crater in the southern hemisphere of Mars. Located just south of the Huygens basin, it could have been carved out by a train of projectiles ...

Recommended for you

Caterpillar comet poses for pictures en route to Mars

10 hours ago

Now that's pure gorgeous. As Comet C/2013 A1 Siding Spring sidles towards its October 19th encounter with Mars, it's passing a trio of sumptuous deep sky objects near the south celestial pole this week. ...

Hoisting a telescope with helium

10 hours ago

Many a child has forgotten to hold tight to the string of a helium balloon only to have it escape and rise until it disappeared in the glare of the sun. Helium balloons want to rise, but launching a balloon ...

User comments : 0