A Martian meteorite is a meteorite that has landed on Earth but is believed to have originated from Mars. This could have been the result of an impact of a celestial body on Mars, sending material from Mars into space. Worlds second largest Meteorite in Culiacan, Mexico A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ... Earth, also known as the Earth or Terra, is the third planet outward from the Sun. ... 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. ...

Note that this does not refer to meteorites actually found on Mars, such as Heat Shield Rock. Heat shield, with Heat Shield Rock just above and to the left in the background (click to enlarge) Heat Shield Rock is a basketball-sized iron-nickel meteorite found on Mars by the Mars rover Opportunity in January 2005. ...

Mars meteorites include three rare groups of achondritic (stony) meteorites (16 objects total) with isotope ratios that are said to be consistent with each other and inconsistent with the Earth. It should be pointed out, however, that the isotope ratios do not actually match Mars ratios especially well, to the extent that Mars ratios are known, although they do differ substantially from Earth isotope ratios and from what is known of Lunar ratios. Worlds second largest Meteorite in Culiacan, Mexico A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ... Isotopes are forms of a chemical element whose nuclei have the same atomic number, Z, but different atomic masses, A. The word isotope, meaning at the same place, comes from the fact that all isotopes of an element are located at the same place on the periodic table. ... 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. ...

All the meteorites are igneous rocks. Lherzolitic shergottites (one from Antarctica, 2 from California) are identified by their Deuterium/Hydrogen ratios. The crystals appear to be 154-187 million years old and they appear, from cosmic ray analysis, to have spent 2.5 to 3.6 million years in space. There are also basaltic shergottites, some of which appear (from the presence of hydrated carbonates and sulfates) to have been exposed to liquid water prior to injection into space. One of the shergottites, known as ALH84001, is much older than the others - about 4.5 billion years. In this respect, it resembles a typical meteorite rather than the other shergottites. The other two types of Martian meteorites are Chassignites and Nakhlites. All appear to have been on earth no more than 35,000 years. Together, these objects are called SNC meteorites. Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... State nickname: The Golden State Other U.S. States Capital Sacramento Largest city Los Angeles Governor Arnold Schwarzenegger Official languages English Area 410,000 km² (3rd)  - Land 404,298 km²  - Water 20,047 km² (4. ... Deuterium (symbol 2H) is a stable isotope of hydrogen with a natural abundance of one atom in 6500 of hydrogen. ... General Name, Symbol, Number Hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1 (IA), 1, s Density, Hardness 0. ... Basalt Basalt is an extrusive igneous rock, sometimes porphyritic, and is often both fine-grained and dense. ...

Although common wisdom is that the SNC meteorites are from Mars, the Mars origin theory does have some problems. The isotope ratios are not an especially good match. A widely published graph showing a near-perfect match is alleged to be constructed from examples selected to "prove" the hypothesis and to be a poor representation of the real data. For example, the Ar40/Ar36 ratio for one meteorite (1650) is almost exactly half-way between Earth (300) and Mars (3000). Carbon dioxide, the predominant gas in the current Mars atmosphere, is unaccountably rare in the trapped gases in the SNC meteorites. The SNC meteorites do not show shock artifacts that would be expected in small objects ejected with enough velocity to escape Mars. The majority of SNC meteorites are quite young by geologic standards and seem to imply that volcanic activity was present on Mars only a few hundred million years ago. Cosmic ray traces in the meteorites indicate relatively short stays (3 to 3.5 million years) in space. It is asserted that there are no large young craters on Mars that are candidates as sources for the SNC meteorites. Earth, also known as the Earth or Terra, is the third planet outward from the Sun. ... A volcano is a geological landform (usually a mountain) where magma (rock of the earths interior made molten or liquid by high pressure and temperature) erupts through the surface of the planet. ...

Possible evidence of life has been hypothesized in three meteorites.

• A 1300-million-year-old meteorite from near Nakhla, Egypt. Small structures that look vaguely like Earth bacteria. More like bacteria than those in the better-known Allen Hills meteorite.

• A 165-million-year-old meteorite from Shergotty, India. Still to be analyzed.

• A 4500-million-year-old meteorite found in the Allen Hills of Antarctica (ALH84001). Ejection from Mars seems to have taken place about 16 million years ago. Arrival on Earth was about 13000 years ago. Cracks in the rock appear to have filled with carbonate materials between 4000 and 3600 million years ago. Evidence of polycyclic aromatic hydrocarbons (PAHs) have been identified with the levels increasing away from the surface. Other Antarctica meteorites do not contain PAHs. Earthly contamination should presumably be highest at the surface. Several minerals in the crack fill are deposited in phases, specifically, iron deposited as magnetite, that are claimed to be typical of biodepositation on Earth. There are also small ovoid and tubular structures that might possibly be nanobacteria fossils in carbonate material in crack fills (investigators McKay, Gibson, Thomas-Keprta, Zare). Micropaleontologist Schopf, who described several important terrestrial bacterial assemblages, examined ALH84001 and opined that the structures are too small to be Earthly bacteria and don't look especially like lifeforms to him. The size of the objects is consistent with Earthly "nanobacteria", but the existence of nanobacteria itself is controversial.

In August 2002, a NASA team led by Thomas-Keptra published a study indicating that 25% of the magnetite in ALH84001 occurs as small, uniform-sized crystals in a crystal form that, on Earth, is associated only with biologic activity. The remainder of the material appears to be normal inorganic magnetite. The extraction technique did not permit determination as to whether the possibly biologic magnetic was organized into chains as would be expected. meteorite fragment ALH84001 ALH84001 (a contraction of Allen Hills 1984 #001) is a meteorite found in Allen Hills, Antarctica in December 1984 by a team of US meteorite hunters from the ANSMET project, among 7,000 others. ... In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ... In chemistry, a hydrocarbon is a cleaning solution consisting only of carbon (C) and hydrogen (H). ... Polycyclic aromatic hydrocarbons, also known as PAH, are chemical compounds that consist of fused aromatic rings and that do not contain heteroatoms and that do not carry substituents. ... General Name, Symbol, Number iron, Fe, 26 Chemical series transition metal Group, Period, Block 8 (VIIIB), 4, d Density, Hardness 7874 kg/m3, 4. ... Magnetite is a magnetic mineral form of both iron(II) oxide and iron(III) oxide or (iron(II,III) oxide), with chemical formula , one of several iron oxides and a member of the spinel group. ... 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. ... A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... Micropaleontology, the study of microfossils, is a branch of paleontology. ... 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. ... 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. ... Note: as an adjective (stressed on the second syllable instead of the first), august means honorable. ... 2002 is a common year starting on Tuesday of the Gregorian calendar. ... SUCK MY WENIS!!! NASA IS A ROCKET SHIP PROGRAM FOR TODDLERS ...

External links

• Mars Meteorite Home Page (JPL) (http://www.jpl.nasa.gov/snc/)