Topographic view of Nirgal Vallis. November 16, 2018. Image via ESA/DLR/FU Berlin.
These new images from ESA’s Mars Express spacecraft, released October 10, 2019, show an ancient, dried-up river system that stretches out for nearly 435 miles (700 km) across the surface of Mars, making it one of the longest valley networks on the planet. This ancient valley system, named Nirgal Vallis, was once filled with running water that spread across Mars. The area lies just south of the planet’s equator, and scientists think it was been shaped by a mix of flowing water and impacts from rocks from space smashing into the Martian surface.
You can see evidence of both of these mechanisms in these images. For example, in the image below, see the impact craters, some large and some small, can be seen speckled across the ochre, caramel-hued surface, and a tree-like, forked channel cuts prominently through the center of the frame.
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The dried-up river valley on Mars named Nirgal Vallis. November 16, 2018. Image via ESA/DLR/FU Berlin.
Nirgal Vallis in context. The area outlined by the bold white box indicates the area imaged ...