Elevation Differences on MarsContrary to the conclusions previously drawn, the polar-cap recession data suggest the dark areas are highlands, because of the greater wind velocities and frost-vaporization rates anticipated for highlands. From the quasi-specular component of the radar power reflectivity and from the radar Doppler spectra, both functions of Martian longitude, the Martian dark areas are found to tend to have systematically higher elevations than the adjacent bright areas. Mean slopes of a few degrees or less are deduced, and elevation differences up to 17 km are inferred. |
Common terms and phrases
15 toward observer 1965 opposition Acidalium adiabatic cooling adjacent altitude difference areas are highlands areas are lowlands Astrophys Astrophysical Observatory bolometric albedo bright and dark bright areas Carl Sagan Cimmerium CO₂ dark areas depressions Doppler spectroscopy dust storm dynamical oblateness Earth elevation differences equation equatorial Exploration of Mars Figure frost deposits Goldstein Goody greenhouse effect heat exchange highland and lowland infrared Journ Kliore latitude line of sight longitude major dark area Mare Australe Mariner 4 occultation Martian atmosphere Martian bright areas Martian dark areas N₂ Natl North American Aviation oblateness of Mars observations of Mars occultation experiment occultation pressures optical oblateness planet planetary polar cap Pollack preferentially quasi-specular component radar reflectivity radar swath superposed radiation Rayleigh scattering rising air Sagan scale height Sinton and Strong Slipher South pole spectrometric pressure subterrestrial point superposed on Dollfus surface pressure Syrtis Major tangent is shown total pressures Vaucouleurs wind velocity