A sometimes-harsh scientific debate has erupted over a new claim that alien fossil bacteria have been discovered within meteorites. This is not connected to NASA’s 1996 announcement that microfossils were found in a meteorite from Mars; that assertion remains highly controversial.
The latest study was published this month in the Journal of Cosmology, whose editor-in-chief is listed as Rudolph Schild of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. The report was authored by Richard B. Hoover of NASA’s Marshall Space Flight Center, Huntsville, Ala.
As leader of Marshall’s Astrobiology Group, in 2009 he won the gold-medal award of the Society of Photo-Optical Instrumentation Engineers. At the time, a NASA press release said:
“In addition, his interest in the origins of life has led to a long chairmanship of the cross-disciplinary ‘Instruments, Methods and Missions for Astrobiology’ conference, an annual three-day conclave of leading astrobiologists and researchers from around the world.
“Hoover has collected meteorites and microbial extremophiles from Antarctica; novel bacteria from the glaciers and permafrost of Antarctica, Patagonia, Siberia and Alaska, and from haloalkaline lakes, geysers and volcanoes of California, Alaska, Crete and Hawaii. He has discovered three new species of bacteria from Mono Lake in California — Spirochaeta americana, Desulfonatronum thiodismutans and Tindallia californiensis — and another, Carnobacterium pleistocenium, which survived for 32,000 years in a frozen Alaskan pond.”
His latest report, which can be read HERE, makes the extraordinary statement that he discovered fossil bacteria when he cracked open three rare carbonaceous meteorites. They turned up when he examined slices of the space rock with field emission scanning electron microscopes.
Carbonaceous meteorites are rare, containing a great deal of carbon as well as evidence for minerals interacting with water; amino acids have been detected in this class of meteorites. According to Georgia State University, these meteorites are dark, containing a tar-like carbon material. The famous Murchison Meteorite, a carbonaceous example that fell in 1969, contains complex organic molecules, GSU adds. “Sixteen amino acids were found in it, eleven of which are rare on the Earth,” GSU says. Although essential for life, amino acids can occur naturally.
“They are thought to originate from dark asteroids called C-type asteroids in the outer part of the asteroid belt,” says the GSU “hyperphysics” Internet site.
Hoover examined the rare group of carbonaceous meteorites called CI1 carbonaceous chondrites. Chemical analysis show they contain clay-like substances that were changed by water at temperatures below 122 degrees F, that is, temperatures at which Earth organisms can thrive. This type of meteorite will disintegrate in water. All known specimens were either discovered shortly after the meteorites were observed falling, or plucked from blue-ice fields of Antarctica.
Careful to prevent contamination by earthly organisms, Hoover fractured samples and examined the newly-exposed surfaces. He avoided fusion crusts and old breaks in the stone.
The field-emission scanning electron microscope turned up tiny filaments that looked like fossils of cyanobacteria. They seemed flattened at one end and cylindrical at the other, with the cylindrical end frequently attached to or embedded in the rock matrix. What looked like empty sheathes that once covered bacteria, similar to cyanobacteria sheathes on Earth, also showed up.
[Field-emission scanning electron microscope view of what may be bacteria fossils from a meteorite. Photo published by Journal of Cosmology]
Hoover added, “It is concluded that the complex filaments found embedded in the CI1 carbonaceous meteorites represent the remains of indigenous microfossils of cyanobacteria and other prokaryotes associated with modern and fossil prokaryotic mats. Many of the Ivuna and Orgueil filaments are isodiametric and others tapered, polarized and exhibit clearly differentiated apical and basal cells.”
The report also posits that life may have originated elsewhere, and developed on Earth from material reaching here from space.
Immediately, the study was engulfed in controversy, with some NASA officials attacking it in statements to the press. Other scientists weighed in, pro and con. One of the critical statements, made available by the Journal of Cosmology on its web site, is by Martin D. Brasier of the Department of Earth Sciences, Oxford University.
Some of Hoover’s filaments could be formations of non-biological origin called ambient inclusion trails (AITs), Brasier wrote. “Such AITs are formed by the forward projection of minerals under gaseous pressure through a solid or liquid medium. Such trails can be recognised by their distinctive infillings with secondary minerals; by longitudinal striations along their edges; by their irregular or polygonal cross sections; by their curved and twisted patterns; and by a tendency for some of them to cross cut or branch …”
[Intrusion trails, not formed through biology. The photo is from Brasier’s critique, published by the Journal of Cosmology]
Brasier added, “Many AITs have a similar composition to those described from the meteorites by Hoover (filaments with margins enriched in carbon and infilled with sulphur and silica rich minerals). Such abiogenic [non-biological] scenarios require rigorous investigation.”
Rigorous investigation is exactly what the research will receive, as scientists continue to examine the results. That’s the scientific method.
Obviously, I am not qualified to judge Hoover’s research. All I can offer is my unscientific gut reaction: his findings seem credible to me.