How deep is the deepest hole ever drilled into the Earth in kilometers?

The deepest hole ever drilled into the Earth is known as the Kola Superdeep Borehole, located on the Kola Peninsula in Russia. The drilling project reached a depth of approximately 12.4 kilometers (7.5 miles), which is recognized as the deepest artificial point on Earth.

This depth was achieved during a scientific research project aimed at studying the geology of the Earth's crust. The Kola Superdeep Borehole provided valuable insights into the composition of the Earth's crust and the conditions at extreme depths. The extensive drilling program was conducted for over two decades, highlighting advances in drilling technology and scientific exploration.

The other options do not accurately reflect the depth of the Kola Superdeep Borehole. For instance, while 10 kilometers, 8 kilometers, and 15 kilometers are numerical values, they do not represent the record depth achieved, which is why they are not the correct answer.