Mars Express images help decipher the geological history of the Red PlanetView gallery - 2 images
New images taken by the ESA’s Mars Express orbiter have provided a fresh look at a region believed to be hiding large volumes of water ice just beneath the surface – something that could serve as a water source for future manned missions to the Red Planet.
The area in question is an ancient Martian mountain range known as the Phlegra Montes, spanning some 1,400 km (870 miles) across the planet’s northern lowlands region. It’s thought to be the product of tectonic forces, which brought it into existence between 3.65 and 3.91 billion years ago.
The new images were captured by the High Resolution Stereo Camera on the Mars Express orbiter on October 8, 2014, focusing on the southern tip of the range. They detail features that add weight to the theory that glaciers once developed in the region, supporting the notion that ice may still reside there today, as little as 20 m (66 ft) below the surface.
Given its position in the mid-latitudes of Mars, you wouldn’t naturally expect to find glaciers in the region. However, it’s thought that the planet has experienced dramatically changing climatic conditions due to a historical variation in the tilt of its polar axis, explaining the strange position of the ancient ice.
An examination of the images reveals multiple small valleys cut through the hills towards areas of lower elevation, as well as aprons of rocky debris surrounding the hills – something that’s caused by the movement of subsurface ice and is routinely seen in glacial regions back on Earth.
The mountainous region sits in stark contrast to the vast, flat plain visible in the upper portion of the observations. Close inspection of the lava plain revealed subtle ridges – features that form as lava cools – that suggest it's the product of volcanic activity originating from the Hecates Tholus volcano some 450 km (280 miles) to the west.
This isn’t the first time that Mars Express has been used to study the geologically turbulent region. Back in 2011, it worked it concert with the Mars Reconnaissance Orbiter to image the range, finding similar evidence of glacial activity, something that points to the presence of water ice not far below the surface.