Scientist Outlines Plan to Probe Earth's Core

May 15, 2003 -- David Stevenson has an idea and he doesn't care if it makes you laugh out loud.

Stevenson, a planetary sciences professor at the California Institute of Technology in Pasadena, has proposed that scientists blast the ground using a nuclear bomb or a few megatons of TNT to create a crack that penetrates some 1,800 miles to the outer edge of Earth's core.

Next, they'd pour in a flood of molten iron that would contain a grapefruit-sized probe within its sloshing path. The probe would then relay back information about inner Earth's temperature and composition using high frequency seismic waves. The probe's journey to Earth's center would take about one week.

The proposal, detailed in the most recent issue of Nature, may seem like science fiction, but Stevenson says it is "modest" compared with NASA's space program. He claims it may seem unrealistic only because little effort has been devoted to the concept.

"If 95 percent of my colleagues read the proposal and laugh and then throw it away, that's perfectly fine as long as 5 percent read it, laugh and say, 'Well, there's a slight chance this could work,'" he said.

Science fiction novels and movies have portrayed people venturing to Earth's center from Jules Verne's 1864 novel Journey to the Center of the Earth, to, more recently, The Core, a 2003 movie starring Aaron Eckhart and Hillary Swank. But, in reality, scientists have only managed to drill down less than eight miles into Earth.

If scientists managed to go much further, as Stevenson proposes, they might find answers to some long-standing questions such as what creates the huge magnetic field around Earth, what exactly makes up the Earth's mantle and core and even whether primitive life exists deep below the crust.

The task is made monumental by the huge amount of energy required to penetrate the dense material of Earth's interior. Scientists estimate the energy required to penetrate Earth is about 10,000,000,000 times greater per distance traveled than the energy needed to blast to the stars.