From Dust Storms on Mars to Streaming in Protoplanetary Disks
Prof. Gerhard Wurm (Univ. Duisburg-Essen)
On Mars dust storms can rage the whole planet and dust devils frequently cross its barren land. Such dusty phenomena are not unknown on Earth but what looks like physics well understood has to be different on Mars on second thoughts. The pressure is only a few mbar at the red planet’s surface and dust is not easily picked up in such a thin atmosphere. One clue to explain particle entrainment anyway is that at low ambient pressure gas no longer follows the rules we know so well. Gas can creep along surfaces from cold to warm sides, somewhat counterintuitively. Pressure in connected reservoirs no longer equilibrates but pressure can built up within the Martian soil, which might explain some of the dust lifting going on.
Different story - similar physics, some not so ordinary interaction between gas and solids might also be important in protoplanetary disks. Here, km-size planetesimals to become a Mars or an Earth in the future form from dust. So called streaming instabilities, concentrations of dust in the disks’ thin atmospheres, are one favorite these days to explain planetesimal formation.
These effects can be studied in laboratory experiments, on ground as well as under microgravity and this talk will focus on some of the recent developments of such experiments.
Student event: Meet the speaker
We invite you to a student-only discussion-round with Prof. Dr. Gerhard Wurm before his Munich Physics Colloquium talk. Be curious and feel free to ask any question.
Monday, 18th of June 2018, 16:00 h, Room H 522 (5th floor), Fakultät für Physik der LMU, Schellingstraße 4, München.