Mars meteorite

related topics
{island, water, area}
{acid, form, water}
{math, energy, light}
{specie, animal, plant}
{work, book, publish}
{god, call, give}
{rate, high, increase}

A Martian meteorite is a meteorite that has landed on Earth and originated from Mars. This could have been the result of an impact of a celestial body on Mars, sending material from Mars into space. Of over 50000 meteorites that have been found on Earth, currently 95 have been identified as originating from Mars, most of which have been found since 2000.[1] Chemical analysis of the martian meteorites suggests that the ambient near-surface temperature of Mars has most likely been below 0 C° for the last four billion years.[2]

Note that this does not refer to meteorites found on Mars, such as Heat Shield Rock.

Contents

History

In 1983 it was suggested by Smith et al. [3] that meteorites in the so called SNC group (Shergottites, Nakhlites, Chassignites) originated from Mars, from evidence from an instrumental and radiochemical neutron activation analysis of the meteorites. They found that the SNC meteorites possess chemical, isotopic, and petrologic features consistent with data available from Mars at the time, findings further confirmed by Treiman et al. [4] a few years later, by similar methods. Then in late 1983, Bogard et al. [5] showed that the isotopic concentrations of various noble gases of some of the shergottites were consistent with the observations of the atmosphere of Mars made by the Viking spacecraft in the mid-to-late 1970s.

In 2000, an article by Treiman, Gleason and Bogard gave a survey of all the arguments used to conclude the SNC meteorites (of which 14 had been found at the time) were from Mars. They wrote, "There seems little likelihood that the SNCs are not from Mars. If they were from another planetary body, it would have to be substantially identical to Mars as it now is understood."[6]

Composition

33 of the 34 Martian meteorites are divided into three rare groups of achondritic (stony) meteorites: shergottites (24), nakhlites (7), and chassignites (2), with the oddball meteorite ALH 84001 not usually placed in a group.[7] Consequently, Martian meteorites as a whole are sometimes referred to as the SNC group. They have isotope ratios that are said to be consistent with each other and inconsistent with the Earth. The names derive from the location of where the first meteorite of their type was discovered.

Full article ▸

related documents
Earth observation satellite
Salinity
Vatnajökull
Fen
Lagoon
Geography of The Gambia
Avon River (Western Australia)
North China Plain
Wolf Point, Montana
Gulf of Saint Lawrence
Distributary
Wyperfeld National Park
Island of Montreal
North Frisian Islands
Alabama Hills
Red River of the North
Kauai
Geography of France
Lizard Island National Park
Mount Holyoke
Mount Royal
Frobisher Bay
Baie des Chaleurs
Banks Island
Thasos
Rügen
Bald Rock National Park
Narawntapu National Park
River Little Ouse
Asthenosphere