The Cold War between the U.S. and the U.S.S.R. brought about several competitions between the two nations. The best known is the space race, in which the Soviets were the first to orbit the earth, while the Americans were the first to walk on the moon. Americans also barely beat the Soviets to the deepest depth of the ocean. Another “race” was to dig the deepest hole into the earth -for scientific purposes, of course. While the U.S. abandoned their "Project Mohole" due to lack of funds, the Soviets drilled for 14 years, producing the Kola Superdeep Borehole which goes down over seven miles.
In actuality, the Kola Superdeep Borehole consists of several holes branching from one central hole. The deepest of these, named "SG-3", measures just nine inches in diameter but extends 12,261 meters (or 7.5 miles) into the Earth. That's roughly a third of the way through the Baltic continental crust. To meet scientific objectives and provide a nearly continuous look at the crust's profile, the Soviets even developed instruments to take direct physical measurements at the bottom of the borehole. The drilling apparatus thus allowed for greater measurement integrity since rock samples would deform under their incredible internal pressure when brought to the surface. Needless to say, the project produced enormous amounts of geological data, most of which elucidated how little we know about our planet.
Not only geological, but biological discoveries were made at tremendous depths. From looking at the picture above, you'd never know this is a world-record-breaking spot. Read about the Kola Superdeep Borehole and what was found there at Atlas Obscura.
Read about what didn’t happen right here. -via Metafilter
(Image credit: Rakot13)