Re-creating Creation In The Beginning . . . There Was Hydrogen, Ammonia, And Methane, Scientists Believe. Then There Was Life. How Did It Happen? They're Mixing Those Substances In An Flask To Figure It Out.

At least once in the history of the universe, the inanimate materials of a newborn and sterile planet - hydrogen, ammonia and methane - gathered themselves into organisms.

And life on Earth began.

Scientists don't see any miracle in this creation. Life came about from a series of chemical reactions, says Jeffrey Bada, a chemist from the Scripps Institution of Oceanography in La Jolla, Calif.

To demonstrate how the spark of life might have taken hold on Earth, he and his colleagues are trying to coax it to happen again - in their laboratory flasks.

If scientists succeed, they will have done for the origin of life what Darwin's evolution did for the origin of mankind - taken it out of the realm of theology and placed it within the laws of nature.

So far, science has produced some of the steps along the path from inanimate matter to the animate - steps that are helping them decode the formula for the origin of life.

Bada is part of a NASA-sponsored team of ``exobiologists,'' people who study the question of life beyond Earth.

Since scientists haven't actually found life on any other planets, Bada takes an indirect route to exobiology, looking at Earth life to determine the probability that life exists elsewhere. Was life an improbable accident that happened only once? Or was it an inevitable outcome of the laws of chemistry - a phenomenon that could have happened in many places throughout the universe?

Last summer's claim of past life on a Martian meteorite did shift the focus in the exobiology community to the red planet, but when Bada, along with colleague Luann Becker, studied a piece of one of these Martian rocks, their analysis cast doubt on the claim of past life.

Bada and Becker contend the organic chemicals found in the rock came from Earthly contamination.

That doesn't rule out the possibility that Mars did harbor life, notes Bada. It's just that no evidence has been found yet.

So the exobiologists turn back to Earth.

The quest to re-create the origin of life in a laboratory began in 1953, with a 23-year-old graduate student named Stanley Miller.

At that time, biologists and chemists had taken apart living cells, revealing the internal working parts, like the gears and coils that run mechanical watches. They found DNA, proteins, sugars, amino acids, and other so-called organic chemicals that no one had seen in matter that hadn't once been alive.