A regional dust storm is currently sweeping across Mars. But is not a major concern for the three landers approaching the red planet, even if it were to grow into a global storm, scientists have told New Scientist. Joy Crisp, mission scientist for NASA’s two Mars rovers, says the storm is unseasonal. Dust storms usually occur from spring to early summer, but it is now late summer to early autumn in Mars’ southern hemisphere. They also usually die out within a week. “We’re probably going to be okay,” says Crisp, at NASA’s Jet Propulsion Laboratory.