How old is that crater?
When you observe the Moon, do you ever wonder how old the crater you’re looking at is? Wondering is about all you could do for most craters, with the exception of a handful that were dated by studying samples brought back during the Apollo missions that had been shocked or melted during impact. But the formation date of the vast majority of craters was almost entirely unknown… until now.
Sara Mazrouei, her advisor Rebecca Ghent of the University of Toronto, and their colleagues have developed an ingenious new technique for estimating the ages of lunar craters based upon the rockiness of their ejecta. When an impact (‘soil’), appearing as warm spots in a sea of coldness. Over millions of years, these boulders are slowly broken down and covered by dust created by micrometeorite bombardment and by the baking and freezing cycle of each lunar day. It takes about a billion years for boulders to be reduced to dusty rubble and cool as fast as the regolith.
