Fusion project aims to reveal planets' secrets

For the adventurers in Jules Verne's classic novel, all it took to reveal the secrets hidden at the centre of the Earth was a simple trek into the bowels of an extinct volcano.

In the real world, however, scientists have had a harder time determining exactly what rests at the core of our planet. With 3,000 miles of solid and molten rock in the way, drilling barely scratches the surface.

Instead, scientists have had to rely upon the deep echoes that emanate from beneath our feet during seismic events such as earthquakes.

The result is that despite centuries of study, we still have a relatively sketchy picture of the centre of our planet — and are virtually clueless when it comes to the cores of the other planets in our solar system.

With so little firm evidence available, the best scientists could do was to make educated guesses: that the pressures are about 3.5 million times greater than those on the surface and that — despite what it says in A Journey to the Center of the Earth — there are no subterranean caverns filled with dinosaurs.

Now, however, a colossal new experiment could at last transport us to these unexplored depths. At a cost of about $1.8 billion (Dh6.6 billion), the National Ignition Facility in Livermore, California, will focus the world's most powerful laser on to a spot little bigger than a pinhead, recreating — for the briefest of instants — the conditions found at the centre of planets, and even stars.

Fusion power

The ultimate goal at Livermore is to trigger nuclear fusion, as a step towards the creation of fusion power stations, which could provide limitless amounts of clean energy.

In the meantime, however, scientists hope to use the phenomenal power of the laser to simulate the interior of planets.

They can do this by carefully focusing the pulse of intense light — which concentrates energy equivalent to 1,000 times the amount produced more than 10 billion times more than an ordinary household lightbulb — for a billionth of a second.

Using this astonishingly precise laser beam, the researchers will be able to compress material to pressures more than 25 million times those found at sea level.

All this takes a lot of infrastructure. The facility itself is the size of three football pitches, in which the 500 trillion watt laser beam travels through almost a mile of lenses, mirrors and amplifiers.

It is then split into 192 separate beams, which are focused on the centre of a 10-metre-wide reaction chamber coated in aluminium and concrete.

Inside the chamber sits the target — a sample of fluids designed to mimic the make-up of the particular planet being studied.