The Committee to Nuke Elysium

The dust cloud surrounds Mars and reaches altitudes more than 1,000 kilometers (621 miles) from the planet’s surface, said MAVEN lead scientist Bruce Jakosky, also with University of Colorado.

“We think the source is the (Martian) atmosphere, however we have no process to take dust from low altitude to bring it up to 200 kilometers (124 miles). So if the source is the atmosphere, we don’t understand which process is moving them up,” Andersson said.

The dust also could have come from Mars’ moons, Phobos and Deimos, from dust in the solar wind or from comet dust that fills interplanetary space.