- Huge ‘river-like structure’ caputured by Mars Express spacecraft and is almost 1,000 feet (300m) deep
- Experts say the images show a ‘striking resemblance’ to areas of Earth affected by glaciation
They are yet more proof of the red planet’s wet past.
The European Space Agency today released an astonishing series of pictures showing the remnants of a huge river than once ran across Mars.
Taken by the ESA’s Mars Express, they show Reull Vallis, the ‘river-like structure’ is believed to have formed when running water flowed in the distant martian past.
It cut a steep-sided channel through the Promethei Terra Highlands before running on towards the floor of the vast Hellas basin.
This astonishing structure, which stretches for almost 900 mile (1500 km) across the martian landscape, is flanked by numerous tributaries, one of which can be clearly seen cutting in to the main valley towards the upper (north) side.
Experts say the images show a ‘striking resemblance to the morphology found in regions on Earth affected by glaciation’.
‘For example, we can see circular step-like structures on the inner walls of the sediment-filled crater in the foreground of the second perspective view,’ ESA said.
Planetary scientists think that these may represent former high water or glacial levels, before ice and water sublimated or evaporated away in stages at various times.
The new Mars Express image below shows a region of Reull Vallis at a point where the channel is almost 4 miles (7km) wide and 1,000 feet (300m) deep.
The sides of Reull Vallis are particularly s