A mysterious black pebble found by an Egyptian geologist at the Libyan Desert Glass strewnfield provides the first ever evidence of a comet entering Earth’s atmosphere and exploding. This image shows Tutankhamun’s pectoral with a scarab carved from the Libyan Desert Glass. Image credit: Jon Bodsworth. The comet entered the atmosphere above Egypt about 28.5 million years ago. It exploded, heating up the sand beneath it to a temperature...