Scientists were baffled to find microscopic fossils of single-celled organisms 4.3 miles down into the Earth Crust from the bottom of the deepest hole on earth

It’s amazing that we know more about some distant galaxies than we do about what lies miles beneath our very own planet. During the Cold War, there was a race by the United States and the Soviet Union to drill as deep as possible into the Earth’s crust – and even to reach the mantle of the planet itself. The two superpowers at the time decided to embark on the most ambitious projects to drill deeper than ever before.

So in the 1970s, Soviet scientists decided to embark on the most ambitious projects to drill deeper than ever before. Their goal was to probe deeper than humanity has ever done before. For the next 24 years, they drilled on and off into the Earth’s crust. The result of their scientific drilling project is the Kola Superdeep Borehole located in Murmansk Oblast, Russia, the remote region of the Russian Arctic.

The Kola hole reaches approximately 7.5 miles (12 kilometers) below the Earth’s surface and yet still only reaches about 0.2 percent of the distance to the center of the Earth’s crust. The Earth’s core is about 1,802 miles (2,900 kilometers) below Earth’s surface and has a radius of about 2,165 miles (3,485 kilometers).

However, to put that in perspective, the Kola borehole is deeper than the deepest ocean, which lies at nearly 6.8 miles (11 kilometers). The Kola borehole is one of the mega projects ever undertaken by humans. Russian scientists drilled the Kola hole on and off for 24 years from 1970 to 1994. The project attempted to drill as deep as possible into the Earth’s crust. Drilling of the borehole began on 24 May 1970 using the Uralmash-4E, and later the Uralmash-15000 series drilling rig.

So what did they find from decades of drilling?

At about 4.3 miles (7 kilometers) down in the Earth’s crust, Russian scientists found microscopic fossils of single-celled organisms. And at nearly the same depth, they discovered water. They also found that the temperature at the bottom of the hole reached a blistering 356°F (180°C). Being too hot to continue, drilling officially halted in 1994. However, what’s even more impressive is that scientists estimate that the distance to the center of the Earth is nearly 4,000 miles (6,400 kilometers). Considering the Earth’s core is about 1,802 miles (2,900 kilometers), the 7.5 miles depth is barely scratching the surface.

Below is a video about the Kola Superdeep Borehole presented by Hank Green from SciShow. Enjoy!