Northwest Africa 7034, abbreviated as NWA 7034, is a Martian meteorite found in 2011 in Morocco. It is the oldest discovery to date: formed 4.4 billion years ago, this rock holds the secret of the “first ten million years of the history of Mars and, by extension, of all telluric planets including the Earth,” explains Anthony Lagain, a French professor working at Curtin University in Australia. In a study published Tuesday in Nature Communications, the researcher today provides valuable and promising information on this rare nugget: its exact region of origin.
Formed shortly after the appearance of the rocky planets, NWA 7034, also called Black Beauty, is the oldest known Martian pebble. It is all the more unique in that it is impossible to find such ancient terrestrial rocks, plate tectonics bringing them back to the Earth’s core. Exploring its projection site would enrich our knowledge of the early days of the solar system.
In search of the right crater
Black Beauty may weigh only 320 grams, but this fragment was enough to find its provenance. Like any meteorite, it was formed thanks to an asteroid which, by hitting the Martian crust, threw blocks of rock into space, leaving a crater on the surface. Ejected at a speed of 5 km/s, the meteorite traveled through space for 5 to 10 million years.
Who says asteroid, says big crater, at least 3 kilometers in diameter. Problem: there are 80,000 on the surface of the red planet. Thanks to an automatic detection algorithm for these cavities developed with his team, Anthony Lagain has identified 18 of them that could be the origin of the meteorite. The scientists then looked into the geophysical and geochemical properties of the rock, which solved the enigma of its origin. It is using its composition and its age that the pebble delivered the location of its ejection site: it is the Karratha crater located in the southern hemisphere of the red planet, named a city in Australia, the country where Anthony Lagain works.
The objective in the near future would be to send a probe to explore the area and thus obtain information on the formation of rocky planets, including Mars and Earth, 4.5 billion years ago. We could perhaps also understand why we have not yet found equivalents to the blue planet elsewhere. Indeed, the presence of liquid water and the magnetic field protecting against radiation are conditions specific to the Earth and essential for life to develop. To be able to answer these questions, you will have to be patient: between a space mission project and the trip itself, many years can pass.