New research suggests that region is formed by sand and silt deposited by the wind

For the last nine years. NASA’s Curiosity rover has been exploring Mars’s Gale crater under the belief the region was once a lake bed, but a new study from the Faculty of Science at Hong Kong University suggests this might not be the case.

Instead, the research suggests that the region was formed by sand and silt deposited by the wind, which was then soaked by ancient rainfall. The study found that immobile elements – meaning those that stay in the rock rather than dissolving in water – are richer at higher elevations, which is normally seen in wind-blown soils rather than lake deposits. There also appears to be depleted iron levels, suggesting the atmosphere was more like an arid desert than a wet lake.

Planetary geologists aren’t quite willing to throw away everything they know about the crater just yet, and will continue to investigate.

“The data presents challenges to existing hypotheses for both the depositional environment of these rock formations and the atmospheric conditions they formed after,” says Hong Kong University’s Ryan McKenzie. “This work will inspire new and exciting directions for future research.” http://mars.nasa.gov

IMAGES: NASA/JPL-CALTECH/MSSS