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What was special about the meteorite ALH84001?
In August 1996 McKay announced that the meteorite had yielded evidence indicating that primitive life may have existed on Mars. The news came only weeks after the 20th anniversary of the first Viking landing on Mars, which had concluded that the planet was sterile.
What do we mean by a Martian meteorite such as ALH84001?
What do we mean by a “martian meteorite” such as ALH84001? A meteorite found on Earth that appears to have come from Mars.
How do you identify a meteorite Martian?
Without detailed testing, one way to recognize a possible Martian meteorite is to look for obvious fusion crust, which is a thin, black, glassy coating formed on the exterior of all meteorites containing iron-bearing silicate minerals as they plummet and decelerate through Earth’s atmosphere.
Where is ALH84001?
Antarctica
Allan Hills 84001 (ALH84001) is a fragment of a Martian meteorite that was found in the Allan Hills in Antarctica on December 27, 1984, by a team of American meteorite hunters from the ANSMET project.
Is ALH 84001 a meteorite from Mars?
It’s nearly certain that ALH 84001 is from Mars, even though people have never been to Mars and no rocks have ever been collected on Mars. In fact, there are 11 other meteorites, called the SNCs, that are also almost certain to be from Mars.
What is the mass of ALH84001?
Like other members of the shergottite – nakhlite – chassignite (SNC) group of meteorites, ALH84001 is thought to have originated on Mars. However, it does not fit into any of the previously discovered SNC groups. Its mass upon discovery was 1.93 kilograms (4.3 lb).
What type of rock is ALH 84001?
To a geologist, ALH 84001 is an igneous rock, similar to many that crystallized from lava inside the Earth. ALH 84001 is also similar to an important group of igneous meteorites (the diogenites), and was classified as one of them until 1994 when its martian origin recognized by Mittlefehldt (1994).
Is siderite in ALH84001 a terrestrially precipitated magnetite?
Thomas-Keprta et al.(2000 2008) have consistently maintained that the elongated prisms of magnetite found in siderite in ALH84001 are “chemically and physically identical to terrestrially, biologically- precipitated, intracellular magnetites produced by magnetotactic bacteria strain MV-1”. Friedmann et al.