This graphic maps the ground-range projection of a radargram of data collected by the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) during the 1,892nd orbit of the European Space Agency's Mars Express. The orbit crosses the Martian lowland plains of a region named Chryse Planitia. Rim walls and interior ring structures of impact basins produce parabolic-shaded echoes. Color-coding on the base map is topographical information from the Mars Orbiter Laser Altimeter instrument on NASA's Mars Global Surveyor orbiter. The inset shows that parabolic-shaped echoes in the radargram project to circular arcs, indicating the presence of a buried impact basin.

The Mars Advanced Radar for Subsurface and Ionospheric Sounding is an instrument on the European Space Agency's Mars Express orbiter. NASA and the Italian Space Agency jointly funded the instrument.