If you want to live elsewhere in the solar system, Mars is the least-bad choice. These days, the planet is a frigid, poison-soaked desert. But as the dry river valleys that cross its surface suggest, things were balmy enough in the past to allow liquid water.
For decades, scientists and science-fiction authors have toyed with the idea of restoring Mars to that warmer state by “terraforming” it—changing the planet’s climate to make it friendly to Earthlings. Their proposals tend to involve heroic engineering: injecting vast quantities of greenhouse gases into the atmosphere, say, or using nuclear explosives to melt underground ice.
A paper published this week in Science Advances offers an easier method. Samaneh Ansari, a graduate student at Northwestern University, in Illinois, and her colleagues reckon that pumping engineered dust into the atmosphere could warm Mars to the point where much of the water ice that lies beneath its surface would melt, at least in the Martian summer.
The paper is just a proof of concept, with plenty of room to make things more efficient still, says Edwin Kite, a planetary scientist at the University of Chicago and one of its authors. As planets go, Mars is certainly a fixer-upper. But the renovations might be a bit easier than you think.