Cosmic rays will reveal universal secrets

The empty Andes are perfect for undisturbed observing

Construction has begun in Argentina on the world's biggest cosmic ray observatory. Its telescopes will scour the heavens for clues which may solve mysteries surrounding the Big Bang, black holes and sub-atomic particles.

Over 1,600 self-operating optical telescopes will be scattered across a desolate 3,000 square kilometre site high in the Andes. These will be paired with a similar array in Utah, US, to seek and measure storms of cosmic rays

Colliding galaxies may produce cosmic rays

Cosmic rays are super-fast protons and have the highest energy levels of any known particle in the Universe. But the source of the most energetic of these particles is "a complete mystery", according to Nobel prize winner Dr James Cronin. He is co-director of the Auger Project and a physics professor at the University of Chicago.

The Argentine government will put $15 million toward the expected $50 million cost of building the observatory.

New astronomy

The array of telescopes, sited 1,100 km (680 miles) west of Buenos Aires, will be hooked up to a central computer to measure the intensity of the cosmic rays.

"It's best to think of this as a new astronomy where there are sources in the Universe which give not light, but very high energy particles," Dr Cronin said.

Most cosmic rays are believed to originate in supernovae but the source of the most energetic is not known - black holes and gamma ray bursts have both been suggested. Other scientists believe cosmic rays may be decayed leftovers from massive particles created in the very early Universe, shortly after the Big Bang, said Leeds University physics professor Alan Watson, the Auger Project's other co-director.

"It may also be that these particles are created by the matter surrounding black holes, or maybe there are particles in nature we have not yet observed with accelerators," said Professor Watson.

A prototype cosmic ray detector

Argentina hopes that the project will pay economic dividends and raise its status in the scientific community, said Alberto Etchigoyen, Argentinian co-ordinator of the Auger Project.

The Argentine part of the observatory is named after Pierre Auger, the scientist who discovered extensive atmospheric storms of cosmic rays in 1938.

It should be completed by 2004, but individual arrays should begin operating within a year, said Dr Cronin.