Archeologists have already established that Viking explorers beat Christopher Columbus to America by about 500 years, but experts in Sweden now hope to determine whether another group of Scandinavians landed in the New World in 1362, 130 years before Columbus. A 90-kilo (200-pound) rune stone, a block of stone featuring symbolic engravings common during the Viking era, has been sent from the United States to Sweden's Museum of National Antiquities to establish whether it really dates from 1362, as its markings claim, or is just a hoax. If confirmed as an authentic relic, the so-called Kensington stone would prove that another wave of explorers, more than 300 years after the Vikings, made it to the American continent before Columbus did in 1492."The stone is very important. But whether or not history will have to be re-written because of this stone is very difficult to say," museum curator Karl-Olof Cederberg told AFP.