Throughout history, mankind has exhibited a unique attraction for gold. From the enticing warmth of its glow to its treasured beauty when made into jewellery, the metal has an appeal unlike any other. Yet, despite this earth-bound love affair, scientific research is showing increasingly that one of the world's most precious metals has its origins a little further from home.
Origin of Gold – What Astronomers Say
Astronomers at the University of Leicester recently put forward a new theory for the origin of heavy elements such as gold, found on earth. While common elements such as iron are known to have been formed within huge stars exploring as supernovae, at the end of their lives, scattering debris deep into the universe, this process does not explain how the heavier elements were created.
At last years, National Astronomy meeting at the University of Cambridge in April, astronomers Dr. Andrews King and Dr. Stephen Rosswag explained that gold and other heavy elements are formed in the violent collisions between neutron stars. They can be found orbiting in pairs around each other and will, at times, collide, unleashing one of the most powerful explosions known in the universe.
Neutron Stars
Neutron stars are very small, superdense stars composed mostly of neutrons. They are formed when massive stars explode as supernovae, during which the protons and electrons of the star's atoms merge to make neutrons. A neutron stars may have a mass up to that of three suns, compressed into a globe measuring a few miles across, and density up to a million times.
A supernova explosion emits a burst of gamma rays before the neutron stars merge to from a black hole,with materials spiralling away as ash at temperatures in excess of one billion degree celsius. The incredible heat triggers nuclear reactions that transform lighter elements into gold and platinum. The newly formed gold is thrown far into space containing such elements as hydrogen and helium – that surround it.
Black Holes
Black holes are objects in space whose gravity is so great that nothing can escape from it, not even light. They are thought to form when massive stars shrink at the end of their lives. Black holes can be detected because gas falling towards them becomes so hot that it emits X-rays.
Predictions Turn Reality
Calculations by astronomers reveal that the relative amount of gold and other elements, such as platinum, existing in the solar system match their predictions, providing strong evidence that these metals were indeed formed during the violent collisions of distant stars.
The relationship between gold and space was highlighted in the study conducted by NEAR (Near- Earth Asteroid Rendezvous) Shoemaker spacecraft about the asteroid Eros. The data collected by NEAR at it passed close to the asteroid revealed that this 33 km long space debris, could be a veritable gold mine in space.
Asteroids
Asteroids are minor planets, composed of rock and heavy elements, that orbit the sun. Most lie in the belt between the orbits of Mars and Jupiter. They include Ceres (the largest), Vesta (the brightest), Eros, learus, Appolo, Asteroids and the Irajans. Appolo asteroids cross the earth's orbit. The orbits of some others are close to that of the earth's.
Eros
Eros is the asteroid discovered in 1898, that can pass 22 million km from the earth. Its orbit comes within that of Mars. It is elongated and measures about 36 x12 km. It rotates around its shortest axis every 5.3 years, and orbits the sun every 1.8 years.
In Greek mythology, Eros represents the boy-god of love, traditionally armed with bows and arrows. He is similar to the common god, Cupid.
NEAR
The Near Earth Asteroid Rendezuous satellite (NEAR) was launched by NASA in February 1996, to study Eros. Its mission was to ascertain what asteroids are made of. It took three years to reach Eros. The satellite spent an year circling the asteroid in a attempt to determine the similarities between asteroids and meteorites.
Images projected down from NEAR enabled scientists to estimate the mass and size of Eros. Taking into account Eros' longer length and girth, some scientists believe that the asteroid could maintain as much as $ 1000 billion of the precious metal.
Mining in Space – How much Practicable?
In a venture that appears to enter the realms of science-fiction, the US commercial space-exploration company believe that even after considering the huge economic aspects, mining asteroids for their metals is a very real prospect. SpaceDev, as the company is known, is committed to the idea of launching a privately financed NEAP (Near Earth Asteroid Prospector) satellite. NEAP targets the asteroid belt that exists between the orbits of Jupiter and Mars and containing a staggering amount of untapped raw materials.
However it is far beyond current technology to even think about moving such massive objects. The asteroids are to be visited to assess their resources and these findings could potentially help to overcome any problems with fuelling longer projects. The refuelling could be done without returning to earth, by utilizing the resource such Near Earth Objects.
NEOs
Near Earth Objects, or NEOs, are believed to be dormant comets. These contain water and could used to refuel rockets. However, this is a close-to-dream technology of the future.
What the Scientific Community Says
Dr. John Lwis, author of Morning the Sky, has said that there are numerous asteroids and comets within easy reach of the earth, with many containing large amount of gold and other valuable materials far purer than the ores found on earth.
The smallest-known earth-crossing asteroid Amun contains trillions of dollars worth of precious and strategic metals. Others contain enough potential rocket propellants to fuel an ambitious programme of solar system exploration for millions of years to come, says Dr. Lewis.
Jim Benson, the founder director of SpaceDev Company says "Scientists have analysed hundreds of these asteroids and know their content precisely. The average metallic meteorite contains about 100 times the concentration of gold as any mine on earth".
Deep Space Mining – New Arenas
Northern Centre for Advanced Technology (NotCat) in Ontario, Canada, is currently working to develop a drilling device that can be operated in low gravity conditions and anchored to the surface of a body in space. The Boeing Company has announced that it is joining hands with SpaceDev to drill out gold from the core of dead comets and asteroids in the next 20 years.
Our Gold Mines
India has three important gold fields, Kolar and Hutti gold fields in Karnataka and Ramagiri gold field in Andhra Pradesh. The total gold metal ore reserves here are estimated at 176.9 lakh tonnes, with 66.7 tonnes metal.
Yes, a new era is beginning in space technology and a saga of human triumph over the endless ocean of eternal silence. Asteroids, meterorites and lifeless planets are no longer useless chunks of space debris. They can be the real elixir of life – as somebody said: "Myths never die, but realities may ......."
Courtesy: Gold Magazine, Spring 2004.
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