Multiple filaments and sheaths embedded in this meteorite could point to extraterrestrial life, says NASA scienist Richard Hoover. ((Richard Hoover/The Journal of Cosmology))

A NASA scientist says he has found fossilized evidence of alien life in the remains of a meteorite, which if confirmed would bolster the theory that life is not restricted to Earth.

The claim that several types of meteorites contain fossils of microscopic creatures similar to cyanobacteria — also known blue-green algae — that originated beyond Earth has predictably created a stir, and 100 experts have been invited to review the research.

Astrobiologist Richard Hoover, who works at NASA's Marshall Space Flight Center in Huntsville, Ala., made the claim in a study published online late Friday in the peer-reviewed publication, The Journal of Cosmology.

The journal's editor-in-chief, Rudy Schild, says Hoover is a highly respected scientist with a prestigious record of accomplishment at NASA. Nevertheless, Schild says he has invited 100 experts to review Hoover's findings and will publish their commentaries online this week.

"No other paper in the history of science has undergone such a thorough analysis, and no other scientific journal in the history of science has made such a profoundly important paper available to the scientific community, for comment, before it is published," the journal's website says.

Using a high-powered microscope, Hoover examined the freshly fractured inner surfaces of carbonaceous chondrites, the most primitive of all known meteorites. These meteorites contain large amounts of water and organic material — each of which is necessary for the kind of life found on Earth.

But inside the meteorites, which were discovered in the Antarctic, Hoover found bacteria-like creatures that he concludes did not come from Earth.

NASA distances itself from study

Carl Pilcher, who heads NASA's Astrobiology Institute, said the rocks have been handled for more than 100 years. He said they are likely contaminated with Earth microbes.

The space agency released a statement distancing itself from Hoover's study. In an updated statement Monday evening, NASA said Hoover did not have a Ph.D. — even though his paper in the journal lists him as a Ph.D — and questioned his expertise as an astrobiologist.

"Anyone can call himself an astrobiologist. That doesn't make it so," Pilcher told the Associated Press.

Hoover, whose specialty is the study of microscopic lifeforms in extreme environments such as glaciers and geysers, is not the first scientist to claim extraterrestrial life.

In 1996, NASA researchers published in the journal Science a study of a Martian meteorite found in Antarctica

That study suggested some of the crystals of magnetite — an iron-bearing, magnetic mineral found in the meteorite — were likely the result of biological processes because they looked so similar to those created by bacteria on Earth.

Other scientists have argued that the magnetite crystals could be produced by chemical and physical processes, and even created similar crystals in the lab by heating carbonates.

With files from The Associated Press