A trace humidity sensor for measurement of Martian atmospheric humidity

Kurzfassung

Building a full picture of the atmospheric humidity at the Martian surface is crucial for understanding the Martian climate and its implications for the search for life on the red planet. Current humidity sensors on Mars measure the relative humidity (r.h.) with a typical accuracy of a few %r.h [1,2]. This is generally sufficient for determining the volume mixing ratio of water in the atmosphere when the temperature is low enough, however such sensors can run into difficulty when the temperature is higher and the r.h. drops below the sensor measuring threshold, for example during the day or in drier areas. It would therefore be advantageous to deploy a sensor on Mars which is capable of measuring trace levels of water vapour to fill in the gaps where relative humidity sensors reach their limit. A sensor has been developed at the Planetary Analogs Simulation Laboratory at the DLR in Berlin which could provide a compact solution to this problem.