By studying tree rings and using a dash of astrophysics, researchers have pinned down a precise year that settlers from Europe were on land that would come to be known as Newfoundland. Six decades ago, a husband-and-wife team of archaeologists discovered the remains of a settlement on the windswept northern tip of Newfoundland. The site’s eight timber-framed structures resemble Viking buildings in Greenland, and archaeological artifacts found there — including a bronze cloak pin — are decidedly Norse in style.Scientists now believe that this site, known as L’Anse aux Meadows, was inhabited by Vikings who came from Greenland. To this...