The Shallow Radar (SHARAD) sounder onboard the Mars Reconnaissance Orbiter seeks geologic boundaries in the first tens to thousands of meters (up to 4 kilometers or 2.5 miles) below the surface of Mars.
Mars Reconnaissance Orbiter's Radar, Top View (Artist's Concept)
This image is an artist's concept of a view looking down on NASA's Mars Reconnaissance Orbiter. The spacecraft is pictured using its Shallow Subsurface Radar instrument (SHARAD) to "look" under the surface of Mars.
From its 10-meter (33-foot) antenna, SHARAD transmits radar waves in a frequency band swept from 25 to 15 megahertz, obtaining a 15-meter (50-foot) vertical resolution in free space, which reduces to 10 meters (33 feet) or less in the subsurface. Horizontally, the radar footprint at the surface is about 3 kilometers (1.8 miles) across, but this can be effectively reduced in processing to about 300 meters (980 feet) along the path of the spacecraft. Surface and subsurface features on the order of these dimensions are observable.
Moments after each transmission, SHARAD records radar waves that reflect from the surface and subsurface geologic boundaries with the same antenna. The radar waves are sensitive to changes in electrical properties, typically associated with changes in density and composition, that they encounter within or between layers of rock, sand, water ice, and carbon-dioxide ice. In context with other data, the layering and structures revealed by the radar reflections provide insight into the geological and climatological processes that formed them.
SHARAD was provided by the Italian Space Agency (ASI) and is operated under the direction of Team Leader Roberto Seu at the DIET Department of “La Sapienza” University of Rome. US participants assist with operations and conduct scientific investigations.
Current US investigators:
Prior US investigators:
ASI SHARAD site: http://www.asi.it/en/activity/solar_system/sharad
PSI SHARAD site: http://sharad.psi.edu