Science and Tech FeaturesFive Weirdest Weather Phenomena on Alien PlanetsScience and Tech Features - RSS 2.0
The lightning rocket dust storms of Mars
On Earth, sandstorms can carry dust as high as a mile up into the air. On Mars, dust storms can attain heights of 20 to 30 miles into the atmosphere, expanding globally and obscuring the entire surface for days - even weeks. Without any rain to wash the dust out of the sky, the particles hang in the dry planet's atmosphere far longer than in Earth's - so long that they act as seeds for clouds to form.
But the size of these dust storms isn't the only thing that's impressive about them. When a pocket of dust within a storm is heated by the sun, the surrounding atmosphere warms quickly, creating a temperature discrepancy on the cold planet. Since hot air rises and cold air falls, the pocket of dust is propelled upward at 22 mph, like a rocket - 100 times faster than the convection normally occurring within the storm. As the dust particles rub against one another, friction charges the dust cloud with electrostatic forces that can discharge as lightning bolts. The result is a giant, roiling sandstorm crackling with electricity.