Cone-shaped hills with summit depressions or craters similar to the two examples in this image are common in the northern mid-latitudes of Mars. Their occurrence in plains that are likely to be volcanic in origin, and their shape that is similar to small explosive cones on Earth, are evidence for a volcanic genesis of these cones.

But the details of the surrounding area and the cones, in this case, demonstrate they are too battered by small impact craters and erosion in general to allow a definitive interpretation. They could also be simply erosional outliers of an older terrain. Or, they may be non-volcanic features similar to certain ice-related hills on Earth.

For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona. The image data were processed using the U.S. Geological Survey’s ISIS3 software.