The ejecta deposits around the impact crater Yuty (18 kilometers in diameter) consist of many overlapping lobes. Craters with this type of ejecta deposit are known as rampart craters. This type of ejecta morphology is charac-teristic of many craters at equatorial and midlatitudes on Mars but is unlike that seen around small craters on the Moon. This style of ejecta deposit is believed to form when an impacting object rapidly melts ice in the subsurface. The presence of liquid water in the ejected material allows it to flow along the surface, giving the ejecta blanket its characteristic, fluidized appearance.
Viking Orbiter image 3A07