An international team including a U.S. scientist says it has confirmed life could have come to Earth from space, carried by comets.

To simulate the collision of a comet and the Earth, the researchers shock-compressed an icy mixture similar to what is contained in comets and found the shock created a number of amino acids, the building blocks of life.

The experiment confirmed something Lawrence Livermore National Laboratory scientist Nir Godlman first predicted using computer simulations on the lab's supercomputers.

Goldman's work had predicted simple molecules found in comets, such as water, ammonia, methanol and carbon dioxide, could have supplied the raw materials, and a collision with early Earth would have yielded an abundant supply of energy to drive this prebiotic chemistry.

Collaborators in Britain conducted experiments recreating Goldman's simulations in which a projectile was fired at high speed into a typical cometary ice mixture, with the result that several amino acids were formed, an LLNL release reported Sunday.

"These results confirm our earlier predictions of impact synthesis of prebiotic material, where the impact itself can yield life-building compounds," Goldman said.

"These results present a significant step forward in our understanding of the origin of the building blocks of life," he said.