Jun 25, 2018
Dust storms occasionally engulf Mars.
On Mars, dust storms are not diffuse and separated like those on Earth, they are caused by tornado-like whirlwinds whose tops reach higher than Mt. Everest. They appear to draw surface dust up through thousands of sky-high funnels and carry it for hundreds of kilometers. Recently, planetary scientists report that another of the world-spanning events is affecting the two active rovers on the surface.
Mariner 9 was the first spacecraft designed to orbit Mars. When it arrived in 1971 NASA scientists saw something completely unexpected: a dust storm so thick that only the top of Olympus Mons penetrated through the clouds. The question is, how can an atmosphere less than one percent of Earth’s density lift dust from the regolith and accelerate it to 50 or more kilometers?
In June 2001 the Hubble Space Telescope observed a dust storm in the Hellas Basin of Mars. The dust clouds spread, but retreated. Suddenly, in only a few days, they moved north and east, until, in a matter of weeks, dust covered the entire planet.
The air is 100 times thinner on Mars and averages 75 degrees colder than Earth. The environment appears to be bone dry, with only some suggestive experiments by the Phoenix lander to indicate the possible presence of water ice. Yet, Martian dust storms are larger than any seen on Earth. Occasionally, when Mars is closest to the Sun, dust obscures the whole planet. Most likely it is those previously mentioned “sky high” vortices that are forcing the dust plumes to rise into the atmosphere.
A previous Picture of the Day reported the surprising discovery of dust devils spinning across the Martian deserts. Cameras in space, as well as on the Martian surface, returned many images of large, glowing funnels raking across the flatlands, leaving darkened trackways behind.
When NASA studied dust devils in the Arizona desert in order to understand more about the ones seen on Mars, they found electric fields up to 10,000 volts per meter associated with dust devils on Earth. The normal fair weather electric field at the Earth’s surface measures between 100 and 400 volts per meter. This suggests that dust devils on both Earth and Mars are atmospheric electric discharge phenomena similar to the electric breezes produced by “ionic wind” air purifiers.
Since Mars has no thunderstorms to “charge-up” its ionosphere, it makes a good case study for Electric Universe theory. An electrical model predicts that the Martian ionosphere is already charged, so electrical effects reach directly from the ionosphere to the surface without the ameliorating effects of storm clouds like those on Earth. Since electrical energy can accumulate in a “planetary capacitor” for some time, there is the potential for planetary-scale events when the atmosphere finally discharges.
Another factor that is associated with the 2001 (largest ever) dust storm on Mars is that it occurred when Mars was close to perihelion, and was the closest to Earth in more than 12 years. At that time, it was close enough to be “tickled” by Earth’s magnetosphere, which established a temporary connection between Earth and Mars, allowing the transfer of electric charge. Mars responded to the increased flux density with an outburst of atmospheric discharges, taking the form of “electrical tornadoes”.
As mentioned, a storm is currently active on Mars, causing NASA’s Opportunity rover to “hunker down” and wait it out. On the other side of the planet, the Curiosity rover will remain operational, because Opportunity is powered by sunlight, while Curiosity has a nuclear-powered battery.
NASA missed a chance to increase its understanding of the electrical environment on Mars with Curiosity. Several years ago, Electric Universe contributing editor, Tom Wilson, suggested installing polarimetry equipment in any Mars lander to observe the polarization properties of particulate matter in the Martian atmosphere. He predicts that the particles will be aligned along an “unexpectedly” strong electric field in the middle atmosphere. Sadly, NASA engineers do not read the Picture of the Day.