Observations of the North Polar Region of Mars from the Mars Orbiter Laser Altimeter

• DOI: 10.1126/science.282.5396.2053
• Publication Date: 2002-07-27T09:44:47Z
• Authors: Maria T. Zuber; David E. Smith; Sean C. Solomon; James B. Abshire; Robert S. Afzal; Oded Aharonson; Kathryn Fishbaugh; Peter G. Ford; Herbert V. Frey; James B. Garvin; James W. Head; Anton B. Ivanov; Catherine L. Johnson; Duane O. Muhleman; Gregory A. Neumann; Gordon H. Pettengill; Roger J. Phillips; Xiaoli Sun; H. Jay Zwally; W. Bruce Banerdt; Thomas C. Duxbury
• Keywords: Orbiter; Atmosphere of Mars

Elevations from the Mars Orbiter Laser Altimeter (MOLA) have been used to construct a precise topographic map of martian north polar region. The northern ice cap has maximum elevation 3 kilometers above its surroundings but lies within 5-kilometer-deep hemispheric depression that is contiguous with area into which most outflow channels emptied. Polar topography displays evidence modification by ablation, flow, and wind consistent primarily H 2 O composition. Correlation images suggests was more spatially extensive in past. volume 1.2 × 10 6 1.7 cubic about half Greenland cap. Clouds observed over are likely composed CO condensed out atmosphere during hemisphere winter. Many clouds exhibit dynamical structure caused interaction propagating wave fronts surface topography.