For years, historians have placed the time Vikings from Greenland settled down in Canada as roughly 1,000 years ago. One research study has now settled on a year: 1021 A.D. Led by an archeologist at the University of Groningen in the Netherlands, the study used spike levels of radioactive carbon found on tree rings—likely caused by large solar flares—to determine when a group of 100 Vikings set up camp in Newfoundland. “Previously the date was based only on sagas—oral histories that were only written down in the 13th century, at least 200 years after the events they described took place,” Margot Kuitems, the archeologist, said.
The date pinpointing is part of a new phenomenon of using a “cosmic ray event” to backlog specific historical moments. It was used along with an analysis of tree markings caused by metal tools, items Indigenous tribes did not have. “It’s a clever application,” Sturt Manning, a professor of archaeology at Cornell University, said. “This is the first clear evidence of Europeans arriving in North America.”