A team of researchers recently found a previously unknown large valley in Mercury's southern hemisphere.
It extends roughly 620 miles, measures approximately 250 miles across, and has an estimated depth of about 2 miles.
Not only is the feature among the largest of its kind on Mercury, it's one of the newer developments.
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Tom Watters, the lead author of the study and a scientist with the Smithsonian National Air and Space Museum, notes, "Unlike Earth's Great Rift Valley, Mercury's great valley is not caused by the pulling apart of lithospheric plates due to plate tectonics; it is the result of the global contraction..."
Researchers believe the cooling of the planet's interior triggered contractions and bends to occur in the sole outer crust plate, resulting in rocks moving upward and the valley floor falling.