Rampart crater

Rampart craters are a specific type of Martian impact crater which are accompanied by distinctive fluidized ejecta features. The craters are considered to be evidence of ice or liquid water beneath the surface of Mars. The impact melts or boils the water in the subsurface producing a distinctive pattern of material surrounding the crater.

References

* [http://www.aas.org/publications/baas/v32n3/dps2000/396.htm The Role of Subsurface Ice in Rampart Crater Formation]
* [http://solarsystem.nasa.gov/multimedia/display.cfm?IM_ID=824 Viking 1 orbiter image, 1977]
* [http://ifp.uni-muenster.de/spp1115/content/pub/PDF/Reiss_LPI_2005_3012.pdf Ages and Onset Diameters of Rampart Craters In Equatorial Regions on Mars.]
* [http://history.nasa.gov/SP-441/ch7.htm Craters as seen by Viking]