WASHINGTON -- NASA and its top scientists are distancing themselves from a space agency researcher who concludes that he found alien bacterial life in meteorites that were collected many decades ago.

Richard Hoover of NASA's Marshall Space Flight Center in Huntsville, Ala., claims he found fossils that look like the remnants of bacteria in at least two meteorites. His research paper, published online Friday in the Journal of Cosmology, concludes these must have come from outer space.

But his claim has been roundly disputed by other scientists.

"There has been no one in the scientific community, certainly no one in the meteorite analysis community, that has supported these conclusions," NASA Astrobiology Institute Director Carl Pilcher said. "The simplest explanation for Mr. Hoover's measurements is that he's measuring microbes from Earth. They're contamination."

In the paper, Hoover states that chemical analysis makes it unlikely to be contamination. Instead, he wrote they are "indigenous fossils" from outer space rather than something found on Earth.

Scientists inside and outside the space agency have criticized and even ridiculed Hoover's study, his credentials and the journal itself. They say that Hoover works in solar physics and doesn't have expertise in astrobiology.