Dust eruptions by photophoresis and solid state greenhouse effects.
We carried out experiments that show a gas pressure dependent ability of light to eject particles from a dust bed. Dust eruptions also occur upon removal of the light source. This can be attributed to a solid state greenhouse effect and photophoretic forces. This ejection mechanism works at light intensities larger than 6 kW/m2 but in extreme cases might work as low as 1 kW/m2. It can be applied to sunlit dust on Mars where it aids or triggers dust lift-off from the surface into the atmosphere. It is of importance for dusty bodies at the inner edge of protoplanetary disks where it leads to light induced erosion. The effect also offers a base for technical applications of dust removal in low pressure environments.
Wurm
Gerhard
G
Institute for Planetology, University of Münster, Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany. gwurm@uni-muenster.de
Krauss
Oliver
O