Orgueil is a scientifically important carbonaceous chondrite meteorite that fell in southwestern France in 1864.

History

The Orgueil meteorite fell on May 14, 1864, a few minutes after 20:00 local time, near Orgueil in southern France. About 20 stones fell over an area of 5-10 square kilometres. A specimen of the meteorite was analyzed that same year by François Stanislaus Clöez, professor of chemistry at the Musée d'Histoire Naturelle, who focused on the organic matter found in this meteorite. He wrote that it contained carbon, hydrogen, and oxygen, and its composition was very similar to peat from the Somme valley or to the lignite of Ringkohl near Kassel. An intense scientific discussion ensued, continuing into the 1870s, as to whether the organic matter might have a biological origin.

Curation and Distribution

Orgueil specimens are in curation by bodies around the world. Given the large mass, samples are in circulation for nondestructive (and with sufficient justification, destructive) study and test. ''Source: Grady, M. M. Catalogue of Meteorites, 5th Edition, Cambridge University Press''

Composition and classification

Orgueil is one of five known meteorites belonging to the CI chondrite group (see

meteorites classification In meteoritics, a meteorite classification system attempts to group similar meteorites and allows scientists to communicate with a standardized terminology when discussing them. Meteorites are classified according to a variety of characteristics ...

), and is the largest (). This group has a composition that is essentially identical to that of the sun, excluding gaseous elements like

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...

and

helium Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

. Notably though, the Orgueil meteor is highly enriched in (volatile) mercury - undetectable in the solar photosphere, and this is a major driver of the "mercury paradox" that mercury abundances in meteors do not follow its volatile nature and isotopic ratios based expected behaviour in the solar nebula. Because of its extraordinarily primitive composition and relatively large mass, Orgueil is one of the most-studied meteorites. One notable discovery in Orgueil was a high concentration of isotopically anomalous

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

called "xenon-HL". The carrier of this gas is extremely fine-grained

diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, ...

dust that is older than the

Solar System The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...

itself, known as

presolar grains Presolar grains are interstellar solid matter in the form of tiny solid grains that originated at a time before the Sun was formed. Presolar stardust grains formed within outflowing and cooling gases from earlier presolar stars. The stellar nucl ...

. In 1962, Nagy et al. announced the discovery of 'organised elements' embedded in the Orgueil meteorite that were purportedly biological structures of extraterrestrial origin. These elements were subsequently shown to be either pollen (including that of ragwort) and fungal spores (Fitch & Anders, 1963) that had contaminated the sample, or crystals of the mineral

olivine The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...

Seed capsule hoax

In 1965, a fragment of the Orgueil meteorite, kept in a sealed glass jar in Montauban since its discovery, was found to have a

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

capsule embedded in it, whilst the original glassy layer on the outside remained apparently undisturbed. Despite great initial excitement, the seed capsule was shown to be that of a European rush, glued into the fragment and camouflaged using

coal dust Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form ...

. The outer "fusion layer" was in fact glue. Whilst the perpetrator is unknown, it is thought that the hoax was aimed at influencing 19th century debate on

spontaneous generation Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise f ...

by demonstrating the transformation of inorganic to biological matter.

Claim of fossils

Richard B. Hoover of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

has claimed that the Orgueil meteorite contains fossils, some of which are similar to known terrestrial species. Hoover has previously claimed the existence of fossils in the

Murchison meteorite The Murchison meteorite is a meteorite that fell in Australia in 1969 near Murchison, Victoria. It belongs to the carbonaceous chondrite class, a group of meteorites rich in organic compounds. Due to its mass (over ) and the fact that it was an ...

. NASA has formally distanced itself from Hoover's claims and his lack of expert peer-reviews.

References

External links

The Orgueil meteorite from The Encyclopedia of Astrobiology, Astronomy, and Spaceflight
* {{Authority control Meteorites found in France Astrobiology Hoaxes in science Hoaxes in France 1864 in France 1860s in science