Head of European Prints, Severine Nackers holds a celestial Map of the Southern Sky by Albrecht Durer, at Sotheby's Auction House on March 25, 2011 in London, England. The two woodcut maps depicting the Northern and Southern skies circa 1515, are the earliest printed star charts of their kind ever published in Europe, and are expected to fetch between Ј120,000-180,000 GBP when they go on sale at the “London sale of Old Master, Modern and Contemporary prints” at Sotheby's Auction house on March 30, 2011. (Photo by Dan Kitwood/Getty Images)