After inspecting a meteorite discovered in the Sahara Desert proofs that water existed on Mars 4.4 billion years ago, scientists report.
The mineral makeup of Martian meteorite NWA 7533, discovered in 2012, indicates chemical signatures of oxidation – which is only possible as water formed.
The 84 gram meteorite, labeled partly after its landing spot of North West Africa, was a piece of a cosmic rock that disbanded on entering Earth’s atmosphere.
‘Our samples of NWA 7533 were subjected to four different kinds of spectroscopic analysis – ways of detecting chemical fingerprints,’ said study author Professor Takashi Mikouchi at the University of Tokyo.
‘We found strong evidence for oxidation of magma.
‘Igneous clasts, or fragmented rock, in the meteorite are formed from magma and are commonly caused by impacts and oxidation.
‘This oxidation could have occurred if there was water present on or in the Martian crust 4.4 billion years ago during an impact that melted part of the crust.’
‘[This] would have contributed to planetary warming at a time when Mars already had a thick insulating atmosphere of carbon dioxide,’ said Mikouchi.
NORTH WEST AFRICAN METEORITES
Mass: 84 g
Mass: 320 g
About a decade ago, two meteorites were found in the Sahara Desert, Africa – NWA 7034, discovered in 2011, and NWA 7533, discovered in 2012, from which Mikouchi and partners received a sample for analysis.
NWA is an abbreviation for North West Africa and the number is the order in which meteorites are officially adopted by the Meteoritical Society, an international planetary science organisation.
‘Some of these meteorites contain trapped gas which matches with the Martian atmosphere analysed by the Mars exploration mission, NASA Viking.’
NWA 7533 and the more popular NWA 7034, known as ‘Black Beauty’, are all part of the same category of a minimum of 10 fragments, all with different numbers, according to Mikouchi.
‘These Martian meteorites have distinct, but identical oxygen isotope ratios from other extraterrestrial materials, so we know that they came from the same parent body,’ he told MailOnline.
‘All of them fell on the Earth by the same event, but probably fragmented during atmospheric entry and scattered in the Sahara desert.
‘Later people picked up separately and the fragments acquired different names.’
Fragments of NWA 7034 was granted to the University of New Mexico by an American who acquired it from a Moroccan meteorite dealer.
Several of the Martian meteorites that exist today were discovered in the Sahara by Bedouin tribesmen who realized the rocks can earn a pretty price in the marketplace of Casablanca.