Spacecraft and Instruments
Mars Climate Sounder (MCS)
Scientists will use these measurements to understand how the martian atmosphere circulates and varies over time. The measurements will also help explain how and why the martian polar caps vary in response to the atmosphere and the energy input from the Sun.
How Mars Climate Sounder Works
A sounder is a type of instrument that measures changes in atmospheric temperature or composition with height. Mars Climate Sounder "sees" in 9 channels across the visible and infrared ranges of the electromagnetic spectrum. The visible range is the equivalent of what the human eye can see. Infrared corresponds roughly to heat, so seeing in infrared would be similar to "seeing" how hot something is. One channel in the visible and near infrared range (0.3-3.0 microns) is used to understand how solar energy interacts with the atmosphere and the surface, which helps us understand the martian climate. Eight channels in the thermal infrared range (12-50 microns) are used to measure temperature, pressure, water vapor, and dust. These measurements are what constitute weather and climate.
Mars Climate Sounder looks at the horizon of Mars from orbit to observe the atmosphere in vertical slices, with measurements every 5 kilometers (3 miles) down in each slice through the atmosphere. These "profiles" are combined into daily, three-dimensional global weather maps for both daytime and nighttime. These weather maps will show temperature, pressure, humidity, and dust in various layers of the atmosphere: the same type of information meteorologists use to understand and predict both weather and climate here on Earth.
The Principal Investigator (lead scientist) for Mars Climate Sounder is Daniel McCleese from the Jet Propulsion Laboratory/California Institute of Technology.