by Mark Perew

Posted January 30, 2001

MOFFETT FIELD, Calif. - Some say, that life here began out there. No, this isn't the opening line of a cheesy 70s science fiction show. It may be the conclusion from new astrobiology research announced today.

Using molecules common to interstellar clouds of dust and gas, and kept in conditions found in deep space, four researchers created a black goo of complex organic compounds. Under the microscope, this goo yields unprecedented structures: tiny round bubbles, analogous to cell walls.

Did this goo rain down on Earth and become the first cells? It does appear at least possible, if not likely. Moreover, the conditions for this black rain occur all over the universe. This could mean that the cosmos is filled with life. Drs. Jason Dworkin, Scott Sandford and Louis Allamandola from the NASA Ames Research Center, along with Dr. David Deamer of the University of California, Santa Cruz present their findings in this week's edition of the Proceedings of the National Academy of Sciences.

The investigation began with a vacuum into which100 parts of water, 50 parts methanol, 50 parts ammonia, and one part carbon monoxide were added. While ultraviolet light shined on the mixture, it was cooled to a mere 15 degrees Kelvin for two days, then allowed to warm to room temperature for another two days. Repeating the heating and cooling cycle over 40 days and nights yielded micrograms of black goo filled with organic molecules.

This residue contains a number of complex molecules. When the researchers washed it they found small round blobs that look amazingly like little cells.

But did they just look like cells, or were these truly cell-like vesicles? The researchers were able to introduce a fluorescent dye into the insides of the vesicles. That was a significant event as it proved that there really was an inside and an outside to these infinitesimal pseudocells.

Next, what were these vesicles made of? The walls of cells here on Earth are made of two layers of lipids. Lipids are made of fatty acids, so the researchers introduced a detergent, which is known to break down lipid bilayers. Under the microscope, the fluorescent dye, previously locked inside the vesicles, now was seen all over the slide. The vesicle walls are made, at least in part, of lipids, just like the cells in your body.

Could this goo form in space, then fall to Earth, form vesicles and be part of how life came to be here? It's possible. It may even be necessary.

Having a cell wall is considered by most biologists to be a prerequisite to life. Dr. Randall Gladstone of the Southwest Research Institute, a planetary scientist and specialist in hydrocarbon photochemistry is one who holds this position.

"You need to make your own little environment," Dr. Gladstone commented, "or else you can't protect yourself."

But, this isn't life or proof that life came about through this mechanism.

"It's a long journey to go from these objects, to saying that these compounds kicked started life," he cautioned.

It could be that some of the parts of life come from here on Earth, while other parts form out in space. Some of those terrestrial parts might be the amino acids demonstrated by Urey and Miller in their famous 1959 Science paper. That Dr. Stanley Miller, now a professor emeritus at the University of California, San Diego, edited and approved this paper for the Proceedings.

"This may mean," Dr. Sandford offered, "that life is not endogenous, that life is not exogenous. It may be just a big mess."

One critical point to note is that this experiment uses abiotic processes to create what might be biological components.

"We're showing that a normal process that's happening very often around stars and planets can form biological precursors," continued Sandford. The question of whether or not these compounds will fall on a [planetary] body is pretty much answered."

Dr. Gladstone agrees, "I think it's cool that these things are made so easily."

"It makes the odds that life's out there, measurably higher," concluded Dr. Sandford.

For more information on this research, please go to Vesciles from Space.

Mark Perew> is a freelance writer, a member of the National Association of Science Writers and a JPL Solar System Ambassador.