Today, the Normandy beach once code-named “Omaha” shows few visible signs of the events of June 6, 1944, when more than 160,000 Allied troops assaulted the heavily fortified, German-occupied coastline. But the sand remembers. University of Texas geologist Earle McBride analyzed samples from the beach using optical and scanning electron microscopes and found shiny, angular grains unlikely to have been produced by any natural process. Further testing revealed the shards to be magnetic grains, we knew instantly what they were.” He and his colleagues also identified iron and glass beads formed by the intense heat of explosions. Up to 4 percent of the sand is made up of this shrapnel,the researchers report, but waves, storms, and rust will probably wipe this microscopic archaeology from the coast in another hundred years.—Samir S. Patel