Holden is a 140 km wide crater situated within the Margaritifer Sinus quadrangle region of the planet Mars, located with the southern highlands. It is named after Edward Singleton Holden, an American astronomer, and the founder of the Astronomical Society of the Pacific. Like Gusev, it is notable for an outlet channel, Uzboi Vallis, that runs into it, and for many features that seem to have been created by flowing water. The crater's rim is cut with gullies, and at the end of some gullies are fan-shaped deposits of material transported by water. The crater is of great interest to scientists because it has some of the best-exposed lake deposits. One of the layers has been found by the Mars Reconnaissance Orbiter to contain clays. Clays only form in the presence of water. It is believed that great amount of water went through this area; one flow was caused by a body of water larger than Earth's Lake Huron. Holden is an old crater, containing numerous smaller craters, many of which are filled with sediment. The crater's central mountain is also obscured by sediment. Holden Crater was a proposed landing site for NASA's Mars Science Laboratory, until Gale Crater was deemed a better landing site. Just to the north east of Holden Crater is Eberswalde Crater which contains a large delta. Wikipedia [ - ]

Holden is a 140 km wide crater situated within the Margaritifer Sinus quadrangle region of the... [ + ]