Lyot crater tagged posts

Valley Networks Lyot Crater, rendered here with elevations exaggerated, is home to relatively recent water-carved valleys (white streaks). New research suggests the water came from melting snow and ice present at the time of the crater-forming impact. David Weiss/NASA/Brown University

Present-day Mars is a frozen desert, colder and more arid than Antarctica, and scientists are fairly sure it’s been that way for at least the last 3 billion years. That makes a vast network of water-carved valleys on the flanks of an impact crater called Lyot—which formed between 1.5 billion and 3 billion years ago—something of a Martian mystery. It’s not clear where the water came from...