Dust devils are a regular feature on Mars. Just like those found on Earth, these mini whirlwinds form when parts of Mars are warmed by the sun, causing air above the surface to swirl upward and carry dust with it. But in Mars' lower gravity (38% that of Earth), these devils grow much larger, reachin g up to 8 km (5 miles) in height and speeds of up to 45 meters per second (150 feet per second). They are also a major part of Mars' meteorological cycles, playing a key role in distributing dust across the planet. ...read more read less