Nasa Concept Video Imagines Mars As It Was 4 Billion Years Ago (VIDEO)

[jakeXT]

3. I still wonder what the max pressure on Mars is, and therefore the liquid water range ?

"The air pressure is so low on Mars that even in the most favorable spots, where the pressure is higher than average, liquid water is restricted to the range 0 to +10 °C," says Bob Haberle of the NASA/Ames Research Center. "Fresh water on Mars begins to boil at 10 °C. Here on Earth we can have water anywhere between 0 and 100 °C -- that range is reduced by a factor of ten on Mars."
http://science1.nasa.gov/science-news/science-at-nasa/2000/ast29jun_1m/

No Viking ever included instruments that could measure pressures over 18 mbar, Phoenix could not measure over 12 mbar, MPF was restricted to 10 mbar, and MSL was held to 11.5 mbar. The mean pressure recorded for MSL sol 370 was 11.49 mbar. This indicates that for much or most of that day the actual pressure was almost certainly above the maximum pressure that the Vaisala pressure transducer could measure.

http://davidaroffman.com/photo4_34.html

http://mars.nasa.gov/msl/mission/instruments/environsensors/rems/

The pressure sensor will be located inside the rover body and connected to the external atmosphere via a tube. The tube exits the rover body through a small opening with protection against dust deposition. Its measurement range goes from 1 to 1150 Pa with an end-of-life accuracy of 20 Pa (calibration tests give values around 3 Pa) and a resolution of 0.5 Pa. As this component will be in contact with the atmosphere, a HEPA filter will be placed on the tube inlet to avoid contaminating the Mars environment.

http://msl-scicorner.jpl.nasa.gov/Instruments/REMS/