The location is not what makes this finding surprising. The Sahara has long been a kind of natural archive of the history of Earth and the solar system. Among its sands, scientists have found 40-million-year-old fossils and other meteorites. In 2019, for example, a 4.5-billion-year-old fragment was recovered that, according to recent research, may have come from an ancient, now-vanished protoplanet, possibly as large as the moon.