Radar Soundings of the Ionosphere of Mars
D. A. Gurnett,1*
D. L. Kirchner,1
R. L. Huff,1
D. D. Morgan,1
A. M. Persoon,1
T. F. Averkamp,1
F. Duru,1
E. Nielsen,2
A. Safaeinili,3
J. J. Plaut,3
G. Picardi4
We report the first radar soundings of the ionosphere of Mars
with the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere
Sounding) instrument on board the orbiting Mars Express spacecraft.
Several types of ionospheric echoes are observed, ranging from
vertical echoes caused by specular reflection from the horizontally
stratified ionosphere to a wide variety of oblique and diffuse
echoes. The oblique echoes are believed to arise mainly from
ionospheric structures associated with the complex crustal magnetic
fields of Mars. Echoes at the electron plasma frequency and
the cyclotron period also provide measurements of the local
electron density and magnetic field strength.
2 Max Planck Institute for Solar System Research, 37191 Katlenburg-Lindau, Germany.
3 Jet Propulsion Laboratory, Pasadena, CA 91109, USA.
4 Infocom Department, "La Sapienza" University of Rome, 00184 Rome, Italy.
* To whom correspondence should be addressed. E-mail: donald-gurnett{at}uiowa.edu
