Five centuries before Christopher Columbus set foot in America, the Vikings had already crossed the Atlantic. Using new dating techniques, scientists studying timber buildings at L’Anse aux Meadows on the northern tip of Canada’s Newfoundland, have established the Norse settled in AD 1021, 471 years before Columbus’s first voyage. While it’s already known the Vikings landed in North America, exactly when they settled has remained an estimate, until now. Cat was joined by Dan Snow to speak to archaeologist Birgitta Wallace about this breakthrough research: discover how a long-ago Solar storm provided vital information for the study, the significance of the date, and what's left to be discovered in the future. You can read more about the evidence here.