The findings, published in the American journal Science suggest that organic molecules -- the building block of life -- have travelled to earth in comets and meteorites.

It also solves a 150-year-old puzzle about the structure of molecules, discovered by Louis Pasteur in 1848.

He showed that though molecules in living organisms could exist in two different three-dimensional forms, in reality they were found in only one form -- either right-handed or left-handed.

It has been observed that amino acid molecules are nearly always left-handed while sugars are right-handed.

However, in 1930s scientists discovered that circularly polarised light, a special type of light rarely found in natural conditions, could destroy handedness of aparticular molecule. By observing a region in great Nebula in the constellation of Orion, the international team has found the presence of circularly polarised light there, suggesting that handedness of molecules is destroyed by the polarised light after their birth.

After destruction of a particular handedness, the remaining form came to earth to provide the starting material for life.

According to scientists, circularly polarised light in regions of universe can create a preferred handedness on organic molecules by destroying the other form.

The particular area, observed by astronomers, is known as star birthplace as molecules are born in that gaseous fireball.

Last year scientists at Arizona State University, USA, found large amounts of left-handed amino acids in the Murchison meteorite which fell to earth in 1969 in Australia. The discovery indicated that one-handed organic molecules existed before life began on earth and might have present in the material from which the solar system wasformed.

They used Anglo-Australian telescope at Siding Spring mountain in Australia to discover these special light rays which they hope would make the picture clearer.