Meteorite fragment ALH84001

ALH 84001 (Allan Hills 84001) is a meteorite found in Allan Hills, Antarctica in December 1984 by a team of US meteorite hunters from the ANSMET project. Like other members of the group of SNCs (shergottite, nakhlite, chassignite), ALH 84001 is thought to be from Mars. On discovery, its mass was 1.93 kg. ALH84001 meteorite. ... ALH84001 meteorite. ... Allan Hills is a site in Victoria Land, in the Eastern region of Antarctica, at the end of the Transantarctic Mountains range. ... 1984 (MCMLXXXIV) was a leap year starting on Sunday of the Gregorian calendar. ... ANSMET (ANtarctic Search for METeorites) is a program funded by the Office of Polar Programs of the National Science Foundation that looks for meteorites in the Transantarctic Mountains. ... A Martian meteorite is a meteorite that has landed on Earth but is believed to have originated from Mars. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. It was assigned to the United States in 1889 and is periodically recertified and traceable to the primary international standard, The Kilogram, held at the Bureau International des Poids et...

[edit] History

This rock is theorized to be one of the oldest pieces of the solar system, proposed to have crystallized from molten rock 4.5 billion years ago. Based on hypotheses surrounding attempts to identify from whence extraterrestrial rocks come, it is supposed to have originated on Mars and is related to other martian meteorites. The theory holds that it was shocked and broken by one or more meteorite impacts on the surface of Mars some 3.6 billion years ago, but remained on the planet. It was later blasted off from the surface in a separate impact about 15 million years ago. Following some interplanetary travel, impacted Earth roughly 13,000 years ago. These dates were established by a variety of radiometric dating techniques, including samarium-neodymium (Sm-Nd), rubidium-strontium (Rb-Sr), potassium-argon (K-Ar), and carbon-14.^[1][2] Major features of the Solar System (not to scale, from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth & Moon, and Mars. ... A Martian meteorite is a meteorite that has landed on Earth but is believed to have originated from Mars. ... The Archean is a geologic eon; it is a somewhat antiquated term for the time span between 2500 million years before the present and 3800 million years before the present. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Radiometric dating is a technique used to date materials based on a knowledge of the decay rates of naturally occurring isotopes, and the current abundances. ... The rubidium-strontium dating method is a radiometric dating technique that geologists use to determine the age of rocks. ... Potassium-argon or K-Ar dating is a geochronological method used in many geoscience disciplines. ... Radiocarbon dating is a radiometric dating method that uses the naturally occurring isotope carbon-14 to determine the age of carbonaceous materials up to about 60,000 years. ...

[edit] Possible lifeforms

On August 6, 1996^[3] ALH 84001 became newsworthy when it was announced that it was believed that the meteorite contained traces of life from Mars, as published in an article in Science by Dr. David McKay of NASA. ^[4][5] August 6 is the 218th day of the year in the Gregorian Calendar (219th in leap years), with 147 days remaining. ... 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... The infamous Face on Mars released on July 25, 1976. ... Science is the journal of the American Association for the Advancement of Science (AAAS). ... The National Aeronautics and Space Administration (NASA) is an agency of the United States Government, responsible for that nations public space program. ...

The electron microscope revealed chain structures in meteorite fragment ALH84001

Under the scanning electron microscope structures were revealed that for some time were considered to be the remains—in the form of fossils—of bacteria-like lifeforms. The structures found on ALH 84001 are 20-100 nanometres in diameter, similar in size to the theoretical nanobacteria, but smaller than any proven cellular life^{[citation needed]}. If the structures are really fossilized lifeforms, they would be the first solid evidence of the existence of extraterrestrial life, aside from the chance of their origin being terrestrial contamination. Structures on ALH84001 meteorite Photo credit: NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Structures on ALH84001 meteorite Photo credit: NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... SEM Cambridge S150 at Geological Institute, University Kiel, 1980 SEM opened sample chamber The scanning electron microscope (SEM) is a type of electron microscope capable of producing high resolution images of a sample surface. ... A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... For other uses, see Life (disambiguation), Lives (disambiguation) or Living (disambiguation), Living Things (disambiguation). ... A metre (American spelling: meter; symbol: m) is a unit of length and the current base unit of length in the International System of Units (SI). ... Structures found on meteorite fragment ALH84001 Nanobacteria (sometimes Nannobacteria ) are claimed to be cell-walled microorganisms with a diameter well below the generally accepted lower limit (about 0. ... Extraterrestrial life is life that exists and originates outside the planet Earth, the only place in the universe currently known by humans to support life. ...

The announcement of possible extraterrestrial life caused considerable controversy at the time and opened up interest in Martian exploration. When the discovery was announced, many immediately conjectured that the fossils were the first true evidence of extraterrestrial life—making headlines around the world, and even prompting U.S. President Bill Clinton to make a formal televised announcement to mark the event ^[6]. The presidential seal was first used by President Hayes in 1880 and last modified in 1959 by adding the 50th star for Hawaii. ... William Jefferson Bill Clinton (born William Jefferson Blythe III[1] on August 19, 1946) was the 42nd President of the United States, serving from 1993 to 2001. ...

Several tests for organic material have been performed on the meteorite and amino acids and polycyclic aromatic hydrocarbons (PAH) have been found. The debate if the organic molecules were created by nonbiological processes or are due to contamination from the contact with Antarctic ice is still on going.^[7][8] In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... An illustration of typical polycyclic aromatic hydrocarbons - NASA Crystal structure of a hexa-peri-hexabenzocoronene reported by Müllen and cooworkers in Chem. ...

As of 2006 however, most experts agree that the microfossils are not indicative of life, but of contamination by earthly biofilms. It has not yet conclusively been shown how the features were formed, but similar features have been recreated in labs without biological inputs.^[3] According to the Associated Press, "skeptics have found non-biological explanations for every piece of evidence that was presented on Aug. 6, 1996. And though they still vigorously defend their claim, the NASA scientists who advanced it now stand alone in their belief."^[3] For the Manfred Mann album, see 2006 (album). ... Three small ammonite fossils, each approximately 1. ... Staphylococcus aureus biofilm on an indwelling catheter. ... The Associated Press, or AP, is an American news agency, the worlds largest such organization. ...

Recent studies on ALH 84001 have shown that, although chances are low, eventually, Martian rocks such as ALH 84001 could actually transfer Martian life to earth. 1 in 10 million meteorites from Mars arrives in less than a year, and around 10 rocks that weigh more than 100 grams make the journey in 2-3 years.^{[citation needed]} Bacterial spores, and rock dwelling organisms are speculated to survive in space for 5 years, meaning transfer of Martian life to our planet is entirely possible.

Survival and propagation after arriving, though, would be even less likely. Its native environment is completely unlike anywhere it would land on Earth, as if a deep sea fish suddenly arrived in the middle of the Sahara desert. Mars has an atmosphere many times thinner than that on top of Mount Everest, with almost no oxygen or water. A life form evolved to survive in such conditions would almost invariably find oxygen, water, and dense air to be toxic, as it would the relatively high temperatures^{[citation needed]}: Even the Antarctic does not get as cold as much of Mars does much of the year. However, it is hypothesized that ALH 84001 originated from a time period during which water may have existed on Mars.^[3] Other meteorites that have what may be biological markings have generated less interest because they do not originate from a "wet" Mars. ALH 84001 is the only meteorite collected from such a time period.^[3]

[edit] Origin on Mars

In September 2005, Vicky Hamilton of the University of Hawaii at Manoa presented an analysis of the origin of ALH 84001 using data from the Mars Global Surveyor and Mars Odyssey spacecraft orbiting Mars. According to the analysis, Eos Chasma in the Valles Marineris canyon appears to be the source of the meteorite ^[9]. The analysis was not conclusive, in part because it was limited to parts of Mars not obscured by dust. The University of Hawaiʻi at Mānoa is a public, co-educational university and is the main campus of the greater University of Hawaiʻi system. ... Artists conception of Mars Global Surveyor (NASA) The Mars Global Surveyor (MGS) is a US spacecraft developed by NASA and the Jet Propulsion Laboratory and launched November 1996. ... Artists concept of the 2001 Mars Odyssey Spacecraft 2001 Mars Odyssey is an unmanned spacecraft orbiting the planet Mars. ... Eos Chasma is a chasma in the southern part of the Valles Marineris canyon system of Mars. ... Valles Marineris cuts a wide swath across the face of Mars Valles Marineris (Latin for Mariner Valley, named after the Mariner 9 Mars orbiter of 1971-72 which discovered it. ...

[edit] ALH 84001 in fiction

• Deception Point, a novel by Dan Brown, refers to the ALH 84001 meteorite in its central theme.
• Contact, a 1997 film adaptation of the novel by Carl Sagan, contains footage of President Bill Clinton commenting on the discovery of the possible Martian fossils. This footage was taken out of context so as to be incorporated in the film. It reportedly garnered some minor criticism from individuals in the Clinton administration.

Deception Point book cover Deception Point (2001) is a thriller novel by Dan Brown, the author of The Da Vinci Code, Angels and Demons, and Digital Fortress. ... Dan Brown (born June 22, 1964) is an American author of thriller fiction, best known for writing the controversial 2003 bestselling novel, The Da Vinci Code. ... This article or section contains a plot summary that is overly long. ... 1997 (MCMXCVII) was a common year starting on Wednesday of the Gregorian calendar. ... Contact is a science fiction novel written by Carl Sagan and published in 1985. ... Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer, astrobiologist, and highly successful science popularizer. ... Order: 42nd President Vice President: Al Gore Term of office: January 20, 1993 – January 20, 2001 Preceded by: George H. W. Bush Succeeded by: George W. Bush Date of birth: August 19, 1946 Place of birth: Hope, Arkansas First Lady: Hillary Rodham Clinton Political party: Democratic William Jefferson Clinton (born...

[edit] See also

• Martian meteorite
• Life on Mars
• Panspermia, or more correctly Exogenesis

A Martian meteorite is a meteorite that has landed on Earth but is believed to have originated from Mars. ... The infamous Face on Mars released on July 25, 1976. ... Panspermia is the hypothesis that the seeds of life are in the Universe, that they may have delivered life to Earth, and that they may deliver or have delivered life to other habitable bodies; also the process of such delivery. ...

[edit] References

PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ... Science, the journal of the American Association for the Advancement of Science (AAAS), is one of the worlds most prestigious scientific publications. ... For the Manfred Mann album, see 2006 (album). ... August 6 is the 218th day of the year in the Gregorian Calendar (219th in leap years), with 147 days remaining. ... The Associated Press, or AP, is an American news agency, the worlds largest such organization. ... For the Manfred Mann album, see 2006 (album). ... August 6 is the 218th day of the year in the Gregorian Calendar (219th in leap years), with 147 days remaining. ... Science, the journal of the American Association for the Advancement of Science (AAAS), is one of the worlds most prestigious scientific publications. ... 1996 (MCMXCVI) was a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ... August 7 is the 219th day of the year in the Gregorian Calendar (220th in leap years), with 146 days remaining. ... The National Aeronautics and Space Administration (NASA) is an agency of the United States Government, responsible for that nations public space program. ... For the Manfred Mann album, see 2006 (album). ... August 7 is the 219th day of the year in the Gregorian Calendar (220th in leap years), with 146 days remaining. ... New Scientist is a weekly international science magazine covering recent developments in science and technology for a general English-speaking audience. ...

[edit] External links

• http://www.jpl.nasa.gov/snc/alh.html
• Allan Treiman's dissection of ALH84001 literature for the non-specialist