Mount Everest, the world's tallest mountain, is seven feet higher than previously believed, the National Geographic Society announced last night.

Using Global Positioning System (GPS) satellite equipment, scientists have recalculated the height of the mountain, on the border of Nepal and Tibet, at 29,035 feet (8,850 meters). The previous height, set in 1954 by the Survey of India, was 29,028 feet.

The new calculation was based on data collected May 5 using lightweight GPS equipment that was carried to the mountain's summit by two Sherpas working with mountaineers Pete Athans and Bill Crouse.

"It was pleasant on top of the world that morning, just a little wind and 12 [degrees Fahrenheit] below," Athans said in a statement released by the society. "The equipment worked without a problem."

"This is a very, very accurate reading," said Bradford Washburn, the famous mountain cartographer and honorary director of the Boston Museum of Science, which funded the expedition with the society.

"National Geographic is accepting this new elevation for Everest because it is clearly the most authoritative and thoroughly executed measurement of the highest point on the Earth's surface," said Allen Carroll, the society's chief cartographer.

The scientists also determined that the massive mountain is moving--creeping horizontally toward the northeast at the rate of about 6 centimeters a year, Washburn said. The movement is caused by the geological fault system that created the Himalaya mountains and that continues to slowly shove the Indian subcontinent under Nepal and China.

Mount Everest, the most famous peak in the Himalayas, was first scaled in 1953 by Edmund Hillary and Tenzing Norgay.

Washburn announced the new measurement, which had been kept secret, at the opening reception of the 87th annual meeting of the American Alpine Club. In attendance were several mountaineers who had successfully climbed Everest, including Eric Simonson, who led the expedition that discovered the body of legendary British mountaineer George Mallory on May 1--just four days before the new calculations were made. Mallory, who died attempting to scale the mountain in 1924, was once asked why he wanted to climb Everest.

"Because it is there," he replied.