The planet's interior remains almost as much a mystery as it was when Jules Verne wrote A Journey to the Center of the Earth. The deepest hole ever drilled is the 8-mile deep Kola Superdeep Borehole in Russia, a modest achievement considering that the distance to the Earth's center is nearly 4,000 miles. Deep Earth holds information that could make earthquake and tsunami prediction a credible science as well as yield new insights into historic climate changes. But human exploration of the Earth's interior will have to wait until technology can allow adventurers to survive the searing heat and crushing pressure of Deep Earth.