Martian Atmospheric Pressure Measurement from Space

In order to facilitate human exploration on Mars, a need exists to study weather patterns and atmospheric conditions on Mars. Mars has colder weather than Earth, is known for its dust storms, and has a very thin atmosphere, yet its atmosphere and climate are more like Earth's than any other planet in our solar system. Despite these challenges, NASA scientists believe that Mars is the most promising planet for exploration and habitation. We are developing a new measurement concept that uses differential absorption Lidar system in the 2-μm CO₂ absorption band to measure atmospheric CO₂ and pressure on Mars. By selecting two or more closely spaced wavelengths, one can eliminate the effects of other gases and surface reflections, allowing us to accurately measure CO₂ absorption and determine CO₂ levels and air pressure on Mars. Our simulations show that this system will be able to measure air pressure with 1 Pa precision up to 5 km away, even in the presence of moderate dust, and measure CO₂ and pressure profiles from the surface up to 13 km with a horizontal resolution of 100 km and a vertical resolution of 100 m (400 m during the day). These measurements will improve weather and climate modeling and prediction on Mars.