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Mars Meteorites, Pieces Of The Planet Mars?

The Mars Exploration Rover Opportunity has discovered that a rock dubbed "Bounce" at Meridiani Planum has a very similar mineral composition to the meteorite EETA79001 and likely shares common origins. Bounce itself is thought to have originated outside the area surrounding Opportunity's landing site; an impact or collision likely threw the rock away from its primary home (Courtesy NASA/JSC/JPL).

The meteorite EETA79001, a basalt lava rock nearly indistinguishable from many Earth rocks, provided the first strong proof that meteorites could come from Mars. Originally weighing nearly 8 kilograms (17.6 pounds), it was collected in 1979 in the Elephant Moraine area of Antarctica.

Three distinct subgroups exist under the name SNC meteorites (after Shergotty, Nakhla, and Chassigny). These Martian meteorite subgroups are classified on the basis of mineralogy, but they all share isotopic signatures, petrologic characteristics. Meteorites from Mars give information on the planet mars. . Except for the famous ALH84001, the relatively young crystallization ages (less than 1.4 billion years for all martian rock and 4.5 billion for ALH84001) is surprising if compared to all other chondrites (more than 4.6 billion years!).

Mars Meteorites (give information about the planet Mars): On March 31 1995, the New york Times and Science magazine reported what had long been suspected: a meteorite from Nigeria named Zagami was indeed a piece of the planet Mars ! A analysis of Zagami revealed that gas trapped within its matrix matched the signature of the Martian atmosphere (as determined by Viking lander in 1976). Today, 30 meteorites are classified Martian meteorites. Three distinct subgroups exist under the name SNC meteorites (after Shergotty, Nakhla, and Chassigny). These Martian meteorite subgroups are classified on the basis of mineralogy, but they all share isotopic signatures, petrologic characteristics. Meteorites from Mars give information on the planet mars. . Except for the famous ALH84001, the relatively young crystallization ages (less than 1.4 billion years for all martian rock and 4.5 billion for ALH84001) is surprising if compared to all other chondrites (more than 4.6 billion years!).

There are now 30 meteorites known by chemical analysis to be pieces of the Red Planet Mars, which have been launched from the surface Mars by an asteroid impact. The rocks then orbited the sun and hit the Earth as meteorites. The SNC's (Shergottite, Nakhlite, Chassignite) have always been the most desired meteorites for collectors and are also some of the most valuable. Science is almost certain the SNC Group of meteorites derived from Mars because of their young ages, basaltic composition, and inclusion of gases with the same composition as the Martian atmosphere. Composition of gases of Martian meteorites are almost identical to those of samples tested on the Martian surface by the Viking probe (NASA).

The shergottite subgroup is named after Shergotty, an achondrite which fell in India in 1865. Shergottites are pigeonite and augite-dominated basalts. Shergottites include the well known Zagami (Nigeria 1962) available for collectors sinces many years.

The nakhlite subgroup is named after Nakhla, an achondrite which landed in Egypt in 1911. Nakhlites are augite-rich achondrites. Nakhlites include also Lafayette (Indiana find) and Governador Valadares (Brazil find).

The chassignite subgroup is named after Chassigny, an achondrite which fell in France in 1815. Chassignites are olivine-rich achondrites. Until recently no more chassignite were found, today it's possible to acquire at reasonnable price a piece of the Chassignite called Diderot (NWA2737).