- Apr 13, 2011
When you visit White Sands National Monument in New Mexico, you will witness endless waves of bright gypsum. It's beautiful, but a team of researchers led by scientists at Cornell University was more interested in what was hiding under the sand.
The team used ground-penetrating radar, which has been used to discover more stones near Stonehenge, to investigate the movements of mammoths, humans and giant sloths from 12,000 years ago. These tracks are normally difficult to see unless conditions are perfect. The researchers refer to them as "ghost tracks."