Dust ejection from planetary bodies by temperature gradients: Laboratory experiments |
| |
| Authors: | Thorben Kelling Gerhard Wurm Miroslav Kocifaj Jozef Klačka Dennis Reiss |
| |
| Institution: | 1. Faculty of Physics, Universität Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany;2. Astronomical Institute, Slovak Academy of Sciences, Dubravska 9, 845 04 Bratislava, Slovak Republic;3. Faculty of Mathematics, Physics, and Informatics, Comenius University, Mlynská dolina, 842 48 Bratislava, Slovak Republic;4. Institut für Planetologie, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, 48149 Münster, Germany;1. European Commission, Joint Research Centre, Institute for Environment and Sustainability, Via E. Fermi 2749, I-21027 Ispra, VA, Italy;2. Politecnico di Milano, Dipartimento di Elettronica e Informazione, Via Ponzio 34/5, I-20133 Milano, Italy |
| |
| Abstract: | Laboratory experiments show that dusty bodies in a gaseous environment eject dust particles if they are illuminated. We find that even more intense dust eruptions occur when the light source is turned off. We attribute this to a compression of gas by thermal creep in response to the changing temperature gradients in the top dust layers. The effect is studied at a light flux of 13 kW/m2 and 1 mbar ambient pressure. The effect is applicable to protoplanetary disks and Mars. In the inner part of protoplanetary disks, planetesimals can be eroded especially at the terminator of a rotating body. This leads to the production of dust which can then be transported towards the disk edge or the outer disk regions. The generated dust might constitute a significant fraction of the warm dust observed in extrasolar protoplanetary disks. We estimate erosion rates of about 1 kg s?1 for 100 m parent bodies. The dust might also contribute to subsequent planetary growth in different locations or on existing protoplanets which are large enough not to be susceptible to particle loss by light induced ejection. Due to the ejections, planetesimals and smaller bodies will be accelerated or decelerated and drift outward or inward, respectively. The effect might also explain the entrainment of dust in dust devils on Mars, especially at high altitudes where gas drag alone might not be sufficient. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
