Scientists Uncover What's Left of the Battle of the Bulge

It was, as National Geographic describes it, "one of history's greatest battles." The last major German offensive of World War II, the Battle of the Bulge, fought from December 1944 to January 1945, saw more than 1 million Allied troops repel attacking Germans on a 500-square-mile battlefield across Belgium and Luxembourg. Despite the importance of the site, "little has been published on its material remains," archaeologist Birger Stichelbaut says in a release. It's too large and too densely forested to allow for traditional surveys—which is why Stichelbaut turned to aerial drones. By mounting pulsing lasers to the drones, he and colleagues were able to digitally map a section of the site, discovering more than 1,000 features, from bomb craters to artillery placements.

They surveyed small sections of land with a drone equipped with high-resolution laser detection and ranging technology, allowing them to see through the dense tree cover. "This allowed for traces of the battle to be observed on a scale not known until now," says Stichelbaut of Belgium's Ghent University, lead author of a study published Tuesday in Antiquity. With the knowledge gained, researchers could identify anomalies on larger, low-resolution maps of an area near the Belgian town of Schönberg. Archaeologists visited some of these dugouts, bomb craters, and fox holes, finding the remains of grenades, fuses for artillery shells, and food plates, per NatGeo.

The artifacts and other finds revealed three phases of occupation: an early phase prior to the offensive in which the Allies kept a front line in place using US artillery battalions to the west; a second phase marking the start of the German offensive, when it appeared Germans may have reused abandoned American artillery embankments; and a final phase, the turning point, when a break in bad weather allowed Allied forces to take to the skies "to establish tactical dominance," the study explains, per Live Science. This phase is marked by "numerous extant bomb craters." Researchers hope these mapping techniques can be used to explore other battlefields before they're lost to history and to nature, perhaps leading to their protection as historic sites. (More World War II stories.)