Earth's orbit around the sun is nearly circular, while the orbit of Mars is slightly elliptical. When earth-based radars observe Mars, the echo strength is proportional to the inverse fourth power of the earth-Mars distance. Earth-based radar observations are done near oppositions. Radar echoes for the best oppositions near perihelion are about ten times stronger than the worst oppositions near aphelion. The results of previous observations and the possibilities for oppositions at perihelion (2001, 2003, and 2005) are discussed.
Mars earth-based radar: 1986 results and 1988-1990 opportunities
1987-01-01
Conference paper
No indication
English
Preliminary Mars radar results.
NTRS | 1965
|Thermal Infrared Spectra of Mars Obtained in 1988, 1990, and 1993
British Library Conference Proceedings | 1996
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