Dust Eruptions by Photophoresis and Solid State Greenhouse Effects

Abstract

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.

An insolation activated dust layer on Mars

“…It has been proposed that the traverse of such a pressure minimum Email address: caroline.debeule@uni-due.de (Caroline de Beule) might be sufficient to lift dust (Balme & Hagermann, 2006). Last not least and connecting to the work presented here, Wurm & Krauss (2006) found that illumination of a dust bed at low pressure provides a lift. This was applied to Mars by Wurm et al (2008).…”

Ice particles trapped by temperature gradients at mbar pressure

“…Ice particles are ejected spontaneously from the ice surface at mbar pressure. This might be due to the photophoretic ejection mechanism discussed in [10] and [11]. After the particles are ejected, in general two different types of particle trajectories are observed (Fig.3).…”

ESA Parabolic Flights, Drop Tower and Centrifuge Opportunities for University Students

“…In a low pressure gaseous environment the GTEffect can be established in translucent and dusty bodies through illumination (Wurm and Krauss 2006). It is an interplay of two basic concepts: a solid-state greenhouse effect (G) and a temperature gradient (T).…”