Fossilized bacteria

Italian Team Claims to Have Revived Meteorite Bacteria

By SPACE.com Staff - posted: 03:27 pm ET - 11 May 2001

Fossilized Bacteria Found in Ancient Meteorite

An Italian team reportedly has found and revived bacteria harbored in an ancient meteorite, a finding that points to the existence of extraterrestrial life but has yet to pass scientific muster.

Bruno D'Argenio of the Italian National Research Council (CNR) in Naples and Giuseppe Geraci of the University of Naples discovered the bacteria, called "cryms" or cristallomicrobi, within the crystalline structure of space rocks found in several parts of the world, the Italian newspaper La Stampa reported.

The bacteria could be 2 billion years old and resisted the extreme pressures and temperatures of entering Earth's atmosphere while inside the meteorite, the researchers say. They publicized their findings at a press conference to the Italian Space Agency in Rome, Reuters reported earlier this week.

The bacteria bear DNA chemistry identical to that within Earth-based life, reproduce normally and are sensitive to antibiotics, the researchers say. In addition, the reports indicate the cryms were found in several other Earth rocks -- which could contradict the claim of extraterrestrial origins.

If true, the finding would support not only the existence of life beyond Earth but a theory that life came here from space, rather than emerging from a primordial soup on this planet.

NASA scientist Everett K. Gibson, who has suffered his share of slings and arrows for ongoing work on Martian meteorites that can be interpreted as bearing signs of fossilized life, was quite skeptical of the Italian reports, noting they provided no detail on where the meteorites were found.

Gibson, a senior scientist at NASA's Johnson Space Center, was the co-leader of a group that announced evidence in 1996 that could be interpreted as ancient life in a Martian meteorite.

"In this case," Gibson said of the Italian findings, "there is not enough evidence that we see from the report to assume anything other than the characterization that it's similar to 50 terrestrial rocks," Gibson said. "That strongly suggests that what they are seeing is something from a contaminant."

Those who study early life on Earth use eight criteria for judging whether a sample is likely to bear signs of life, he said. The toughest hurdle requires researchers to demonstrate that the chemistry in their rock comes indeed from the rock, not from chemistry the rock has picked up in its travels.

The Italian sample quite likely was contaminated by Earth bacteria or chemical factors upon arrival, Gibson said, with bacteria borne via atmospheric or surface gases.

"It's extremely likely that [incoming meteorite] material will pick up contaminants from the Earth," he said. "These are terrestrial bacteria. So the burden of proof lies with the investigator to prove that what he has is truly indigenous from the sample he is studying."

In an open letter to La Stampa, Ennio Marsella, also of the CNR, likened his colleagues' findings to the 1996 discovery. He called the creatures "dormant" bacteria with the ability to endure indefinitely within the crystalline structure of rocks.

Cryms measure a few ten-thousandths of a millimeter or smaller, Marsella said. Extracted from rocks on Earth, they can, "with rather simple techniques, once placed in the appropriate conditions," regain mobility and begin to reproduce, he said.

Scientists have long debated the origin of life on Earth, with life dated back 3.8 billion years, just half a billion years after the birth of the planet. Some researchers believe comets transported life to Earth, while others say some form of electromagnetic radiation catalyzed a combination of chemicals on Earth to jump-start life.