The method used by planetary scientists to estimate the ages of various regions of Mars is flawed. “This really changes things,” says Nadine Barlow of Northern Arizona University in Flagstaff. For instance, the findings will significantly change our understanding of when Mars may have been volcanically active. To estimate the age of any region on Mars, geologists count the number of meteor craters they can see in images of the area. The idea is that the older a surface, the more craters should have accumulated over time. Crater counts give an indication of the relative age of different Martian regions.
