Mars Could Have Once Held Water: New Study Finds

Mars could have once held water bodies on its red surface. A new image from ESA's Mars Express provides fresh evidence. The image shows the Nirgal Vallis, which is one of the longest river systems on Mars, which is now dried up.

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Mars Held Rivers

The Nirgal Vallis is believed to have been almost 700 km long and flowed south of the equator. The entire region is believed to be shaped by the water flow and the impact it had on the surface. The new images show a region created by an impact of craters. It indicates that rivers and craters worked together to shape Mars' surface.

The Nirgal Vallis River has significantly contributed to the massive flood that occurred eons ago, scientists believe. The swollen river would have flown into the Holden Crater to create a lake 200-250 m deep. Although an exact timeline can't be placed, researchers think it could have happened roughly 3.7 billion years ago.

River Nirgal Vallis On Mars

The river Nirgal Vallis comes under a feature called amphitheater-headed valley. Here, all the small tributaries merge to form Nirgal Vallis, which is shaped like an ancient Greek amphitheater. The entire surface has a final touch-up of Martian winds to create valley walls.

The new images also indicate that the river surface could have been created by a process called 'Groundwater Sapping'. This occurs when the groundwater doesn't travel vertically and is forced to seep sideways into the layers beneath the surface. This, in turn, creates a head-ward flow of water to form a u-shaped channel, to finally create a round-ended, amphitheater-shaped valley. This feature is dominantly seen on Earth, especially in desert regions.

ESA Mars Express Exploration

Scientists believe that Mars, in many ways, is like a skeleton of the Earth. They believe that Mars once held volcanoes, oceans, rivers, and other water bodies. But now, the volcanoes have dried up and the fumes are long gone. The ESA's Mars Express Orbiter is sending home images and maps of the Mars surface to help understand the Red Planet better.

The Mars Express Orbiter is equipped with a High-Resolution Stereo Camera, which helps scientists understand Mars in its entirety. The Stereo Camera is part of ESA's mission, which also includes the Trace Gas Orbiter and the ExoMars Rosalind Franklin rover.