Two complementary radar sounder instruments work together to discover
hidden Martian secrets. They are the Mars Advanced Radar for Subsurface
and Ionospheric Sounding (MARSIS) on the European Space Agency's Mars
Express orbiter and the Shallow Subsurface Radar (SHARAD) on NASA's Mars
Reconnaissance Orbiter.
MARSIS was designed to penetrate deep and it has delivered on its promise.
This figure shows the base of Mars' south polar layered deposits at the
deepest recorded point of 3.7 kilometer (2.3 miles).
In contrast, SHARAD was designed as a high-resolution radar for a
maximum penetration of 1 kilometer (0.6 mile) has difficulty detecting the
base of these layered deposits.
MARSIS was funded by NASA and the Italian Space Agency and developed by
the University of Rome, Italy, in partnership with NASA's Jet Propulsion
Laboratory, Pasadena, Calif. Italy provided the instrument's digital
processing system and integrated the parts. The University of Iowa, Iowa
City, built the transmitter for the instrument, JPL built the receiver and
Astro Aerospace, Carpinteria, Calif., built the antenna. JPL is a division
of the California Institute of Technology in Pasadena. Additional
information about Mars Express is at www.esa.int/marsexpress.
SHARAD was provided by the Italian Space Agency (ASI). Its operations
are led by the University of Rome and its data are analyzed by a joint
U.S.-Italian science team. JPL, a division of the California Institute of
Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA
Science Mission Directorate, Washington.