Where Martian dust comes from
https://phys.org/news/2018-07-martian.html
"Mars wouldn't be nearly this dusty if it wasn't for this one enormous deposit that is gradually eroding over time and polluting the planet, essentially," said co-author Kevin Lewis, an assistant professor of Earth and planetary science at the Johns Hopkins University.
In the film The Martian, a dust storm leads to a series of events that strands an astronaut played by actor Matt Damon. As in the movie, dust on Mars has caused problems for real missions, including the Spirit Mars exploration rover. The fine, powdery stuff can get into expensive instruments and obscure solar panels needed to power equipment.