Eden Patera is a feature located in the Mare Acidalium quadrangle on the planet Mars. In October 2013 the feature gained some attention when it was speculated it may be a supervolcano rather than an impact crater, according to research from the Planetary Science Institute in Tucson, led by Joseph R. Michalski.[1][2][3]The research postulated the crater was formed by the volcano's caldera collapsing, rather than from an impact.[4] Some of the reasons for suspecting that Eden Patera is a collapsed caldera rather than an impact crater are its irregular shape, an apparent lack of a raised rim or central peak, and lack of impact ejecta.[4]