A deep and wide giant valley has been discovered on Mercury, the innermost planet of the solar system. The discovery was made by researchers from German Institute of Planetary Research, Moscow State University, University of Maryland, and the Smithsonian Institution. The vast valley could hold important clues about the geological history of the planet.

The discovery was made using the stereo images obtained from the MESSENGER spacecraft. The valley is situated in the southern hemisphere and is a part of the Rembrandt Basin, which is a huge crater and has been formed by a meteorite or asteroid collision in the recent past. However, the great valley has been formed not by an impact but by some other cause.

Details of the discovery have been published in the online November 16, 2016, in the journal Geophysical Research Letters. The Earth has a crust and the upper mantle known together as the lithosphere, which is divided into multiple tectonic plates. This is not the case with Mercury which has a solid lithosphere which covers the entire planet. As the planet cooled down some 3 to 4 billion years ago, the lithosphere buckled and formed valleys much akin to a grape which wrinkles when it dries and becomes a raisin.

It is a vast valley, and nothing of such magnitude is seen on the Earth. Mercury has experience buckling of an unprecedented degree. The Valley is about 250 miles wide and 600 miles long. The sides of the valley are 2 miles deep. The Grand Canyon on Earth pales in comparison.

According to the researchers as the interior of Mercury cooled rapidly and formed a strong and thick lithosphere. The floor of the valley is formed by a large piece of lithosphere which dropped between the two faults on the either side. Mercury has been steadily cooling ever since its formation but what interests the researchers is the fact that the planet in recent times has gone through a period of warming. Most of the features on the planet are very ancient, but there is evidence of recent volcanism