Russian scientists have drilled into the vast, dark and unknown Lake Vostok,  2.2 miles below the surface of Antarctica,  Russian news agency RIA Novosti said Monday.

“Yesterday, our scientists stopped drilling at the depth of 3,768 meters and reached the surface of the subglacial lake,” the news agency quoted a source as saying. ".After decades of drilling , Russian scientists have finally managed to pierce through Antarctica’s ice sheet to reveal the secrets of a unique sub-glacial lake, Vostok, that has been sealed there for the past 20 million years, a scientific source said on Monday"

Sergei Lesenkov, spokesman for the Arctic and Antarctic Scientific Research Institute, told Agence France-Presse in Moscow on Monday that there was the possibility of a “fundamental scientific development.”

The  Russian scientists have spent  more than 20 years in this attempt  to drill into the lake, operating in some of the most brutal weather conditions in the world. Their goal   comes just as the Antarctic summer ends at Vostok and the cold becomes so great that machinery can’t be operated and airplanes can’t come in or go out.

The Russian discovery will has create scientific excitement about potentially learning some of the long-held secrets of the largest subglacial lake in Antarctica, a body of water that wasn’t discovered until the mid-1990s and is the world’s third-largest lake by volume.