Previously, mapping required thousands of hand measurements with a theodolite and a transit. This striking map of Mount Everest, created half a century after the first ascent, was built on millions of measurements, but none made by hand. The space shuttle recorded infrared images for reference, then a jet plane took stereophotographs, which were converted to digital data and merged by computer to create the sharpest and most accurate image ever made of the great mountain. Published in May 2003, this map was one half of a two-piece set with "Everest 50."