Problems and New Directions for Electrostatics Research in the Context of Space and Planetary Science

摘要

The lofting, transport, and stratification of particles, dust, and aerosols is a ubiquitous process occurring in many planetary environments. Thus atmospheric electricity and other electrostatic phenomena are very likely to be commonplace on many planetary bodies and moons. At present there are confirmed detections of lightning using optical and radio instruments at Saturn and Jupiter, generated by mechanisms thought to be similar to those found in terrestrial thunderstorms. The presence of lightning on Venus has been inferred through the detection of electromagnetic whistler waves in orbit. The atmosphere of Mars is one compelling example of a system that should possess active electrical processes arising from triboelectric charging, where dust storms are known to occur on local, regional, and global scales. Airless small bodies and moons are also not immune to charging phenomena, which are generated in their case by interactions between their surfaces, plasmas, and sunlight. Looking backwards in time to the early solar system, the dynamic mixtures of gas and dust found in the protoplanetary nebula could also be a likely abode of electrostatic activity. Here we review the current state and overall importance of electrostatic processes throughout the solar system in the past and present. Electrostatic activity on Mars is given focused attention, where recent observations designed to detect the presence of atmospheric electricity have been contradictory, thus leaving this tantalizing question open for additional experiments and future missions. I end by discussing current problems and intriguing new directions for electrostatics research in the context of space and planetary science, ranging from ground-based laboratory experiments, theory and modeling, and exciting new opportunities in the emerging re-usable suborbital vehicle program.