Scientists have hit bottom in the deepest northern ice core ever drilled. The project, known as "NGRIP," studies the historical climate. The deepest ice contains clues from about 110,000 years ago -- a warm period before the last ice age. No other ice core in the Northern Hemisphere is from this epoch. This year's season began with ice dating from the last ice age and gradually worked backward in time as the hole got deeper.

Based on studies of the ice sheet with ground penetrating radar, the researchers knew that they had only about 100 meters to go before they hit the base of the glacier. Ice from this part of the glacier -- less than one percent of the entire project's ice -- is the oldest, and for the researchers, the most important.

Field tests enabled the researchers to estimate when the ice was formed. As they drilled deeper, they found evidence of ice formed before the last ice age. Finally, they reached 3080 meters below the surface, nearly two miles from the top. If the radar studies were correct the bottom of the ice sheet would be somewhere in the next ten meters, with 3085 meters being the most likely depth.

On July 17, at 3084.99 meters below the surface, the drill was lowered down and the motor shorted out. Something had gone wrong. The researchers raised the drill to see what had happened. It takes about an hour to hoist the drill from that depth.

When the top of the drill appeared, Trevor Popp, a graduate student from the University of Colorado, crouched down to see what had happened. "Oh shit," he called out. "We're done." On the bottom of the drill was a brown icicle the size of a roll of paper towels. The icicle was formed from frozen sediment-rich water from near the bottom of the ice sheet.

Dorthe Dahl-Jensen, the project's chief scientist, was there when the drill appeared. She says "I'll never forget it as long as I live." Dahl Jensen said that the water sample could contain live organisms that have lived in the water pocket since the Greenland Ice Sheet was first formed several million years ago.

	Interactive Ice Core Drill Try out a virtual drill to see what it is like to be an ice core researcher. The Deepest Hole The NGRIP drill site is in an extremely harsh and remote location. See pictures of how the scientists conduct their research.