Dust devil trails on the surface of Mars
© NASA/JPL/University of Arizona
Dust devil trails on the surface of Mars
If humans ever land on the surface of Mars, we won’t have to worry about little green men, but the weather is a big concern. These dark trails and swirls were caused by dust devils. Just as on Earth, they’re formed by a mass of cold air colliding with a mass of warm air. This creates a vortex of swirling winds that can turn into a dust devil. The dust devils pick up the thin coating of light-colored dust on the planet’s surface and leave behind dark sand etched in the odd, beautiful patterns of the devils’ tracks. Some dust devils on Mars can be as tall as 5 miles.