Martian Electro-Meteorology

Dr. William Farrell
Laboratory for Extraterrestrial Physics
NASA Goddard Space Flight Center

From our experiences at Earth, we know that electricity and weather are intimately related. Where there is wind-blown ice and water in convective thunderstorms, there is also electricity generated. In this talk, we present evidence that dust storms and dust devils are electrically-active as well. Specifically, we will demonstrate that wind-blown sand/dust grains of various sizes and compositions generate electricity in a process is called "triboelectricity" or frictional electrification. This generation process may be particularly potent at Mars, where the climate is arid and the atmospheric pressure is low. In 1999, LEP scientists won the opportunity to fly an electric package to the Martian surface specifically to quantify triboelectric charging for the first time. Martian electric dust storms may pose a hazard to equipment and future human explorers, and thus the atmospheric electricity package was requested by NASA's Human Exploration and Development of Space (HEDS) enterprise. We will discuss the science motivation associated with that package, along with initial package designs. We will also present some surprising observations from desert field campaigns of terrestrial dust devils carried out by LEP investigators over the last two summers.