In Jules Verne’s A Journey to the Centre of the Earth, the half-crazy Professor Lidenbrock travels with guide Hans and reluctant nephew Axel to the Earth’s centre via an Icelandic volcano. And after many dangerous adventures the trio returns to Earth’s surface again via a volcano in Italy.
More than a century and a half has passed since Jules Verne wrote his famous science-fiction novel, but we are nowhere near reaching the centre of the Earth. We have drilled only 12km deep, and will probably never access the core of iron and nickel so that geologists can examine first-hand how the core formed inside the young Earth.
So instead, scientists are looking the other way – towards space, where asteroids still include all the building blocks that formed the rocky planets of Mercury, Venus, Mars – and Earth. Astronomers have already launched probes into orbit around stony asteroids similar in make-up to Earth’s mantle. Probes have also visited carbonaceous asteroids similar to those which probably provided Earth with water and possibly life.
So far, we have never visited a metallic asteroid. But NASA now has plans to do so, sending the Psyche probe on a 2.4 billion kilometre space mission to
