Digitally Recreating Ancient Buried Structures

"Seventeen centuries ago, North America's Midwest was covered with hundreds of precisely aligned astronomical markers...These geometric structures survived for close to two millennia before most were plowed over in the 19th century, paved over in the 20th century, or destroyed by archaeologists...EarthWorks is the most comprehensive virtual reconstruction of archaeological remnants...Hancock's team used archaeological data gleaned from remote-sensing devices that can detect remains below the ground, and infrared aerial photographs and satellite images..."