What's inside the world's deepest hole?

As the race in space was winding down, soviet scientists turned inwards. You'd never guess that this is the site of one of their great achievements.

This hard-to-find rusty cap in the ruins of a building in Russia's Kola Peninsula covers the deepest hole on earth.

The scientists drilled it off and on for 24 years from 1970 to 1994. They got down as far as 7.5 miles, or about 12 kilometers deeper than the deepest ocean, before blistering heat of 356 degrees Fahrenheit, made them stop.

At 4.3 miles down, the scientists found fossils of single-celled organisms called plankton and water. Deep as the hole bored it made it only two-tenths of one percent of the way to the center of the earth.

The project is a relic of history now but at least it was commemorated with a soviet postage stamp in 1987.

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