Mountains and buried ice on Mars

Mountains and buried ice on Mars.

New images from the high-resolution stereo camera on ESA’s Mars Express orbiter allow a closer inspection [of the Phlegra Montes mountain range] and show that almost every mountain is surrounded by ‘lobate debris aprons’ – curved features typically observed around plateaus and mountains at these latitudes. Previous studies have shown that this material appears to have moved down the mountain slopes over time, and looks similar to the debris found covering glaciers here on Earth.

Mars Express takes a close look at the Mars volcano Tharsis Tholus

Mars Express takes a close look at one of Mars’ giant volcanoes, Tharsis Tholus.

At least two large sections have collapsed around its eastern and western flanks during its four-billion-year history and these catastrophes are now visible as scarps up to several kilometers high. The main feature of Tharsis Tholus is, however, the caldera in its center. It has an almost circular outline, about 32 x 34 km, and is ringed by faults that have allowed the caldera floor to subside by as much as 2.7 km.

Mars atmosphere has more water vapor than predicted

Data from Mars Express has found that the Martian upper atmosphere has far more water vapor than predicted.

“The vertical distribution of water vapour is a key factor in the study of Mars’ hydrological cycle, and the old paradigm that it is mainly controlled by saturation physics now needs to be revised,” said Luca Maltagliati [of the Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) in Guyancourt, France]. “Our finding has major implications for understanding the planet’s global climate and the transport of water from one hemisphere to the other.”

“The data suggest that much more water vapour is being carried high enough in the atmosphere to be affected by photodissociation,” added Franck Montmessin, also from LATMOS, who is the Principal Investigator for SPICAM and a co-author of the paper. “Solar radiation can split the water molecules into oxygen and hydrogen atoms, which can then escape into space. This has implications for the rate at which water has been lost from the planet and for the long-term evolution of the Martian surface and atmosphere.”

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