Martian Dust Storms
The formation of Martian dust storms (and dust storms on the Earth’s surface as well) are due to the surface of Mars being strongly heated by incoming solar radiation that heats up the surface. The air closer to the surface is heated and cooler air is present above it.
The heated and cooler air becomes unstable, and the heated air then rises taking dust up into the Martian atmosphere with it, like thunderstorms on the Earth. Rising plumes of heated air and dust form dust devils (small cyclonic whirlwinds) that grow as more dust is added to them.
The dust devils them coalesce to form massive dust storms over a period of hours to days. Depending upon the size of the dust storm the dust may remain aloft in the Martian atmosphere for days, weeks, or months which then obscures the surface features below. Illustration by Carlos E. Hernandez©
Hellas Basin Dust Storm
The Hellas Basin on Mars is huge impact basin located over the southern hemisphere of the planet (42.40S, 70.50E) and measures 1,400 miles (2,300 km) across and up to 4.4 miles (23,465 feet or 7.2 km) in depth, the deepest point on the planet Mars. The Hellas Basin contains the highest surface pressure on Mars at 12.4 millibars (mbar; 1,240 Pascal (Pa) or 0.18 psi). This surface pressure in the Hellas basin is 2x higher than the average surface pressure on Mars (6.1 mbar, 610 Pa, or 0.09 psi). The surface pressure within the Hellas Basin could theoretically support liquid water under certain conditions of temperature, pressure, and dissolved salt content (but only for brief periods of time). The Hellas Basin is a very common site for the origin of Martian dust storms. My painting of the Hellas Basin before and during a dust storm©.
- Mars
- Oppositions of Mars
- Mars in Retrograde
- Weather on Mars
- Observing Mars With a Telescope
- Learning to Draw Mars Albedo Features
About the author:
Ambassador Carlos Hernandez has contributed his planetary observations to worldwide organizations including The Association of Lunar and Planetary Observers (ALPO, United States), British Astronomical Association (BAA, Great Britain), Oriental Astronomical Association (OAA, Japan), and many other excellent planetary amateur astronomer groups over many decades.