A meteorite that remembers a time before the formation of the Earth
How the planets were formed? This question has troubled scientists for years and is the missing piece of the puzzle in the evolution of the Solar System. Some light has been shed on this issue by studies of the oldest magma meteorite ever found – Northwest Africa 11119.
Scientists are convinced that the Solar System formed about 4.6 billion years ago, when a cloud of gas and dust collapsed under the force of gravity. The beginning of our system was probably given by an explosion from a nearby massive star. Since then, scientists have been able to determine piece by piece how the Solar System was formed.
Scientists from the University of New Mexico, Arizona State University and NASA’s Johnson Space Center have added another piece to the puzzle with the oldest meteorite ever found. Research on the subject appeared in „Nature Communications”.
– This is the oldest magmatic meteorite yet found. It is an unusual type of rock, whichory mowi us that not all asteroids look the same. Someore of them look almost like the Earth’s crust. Appeared during one of the first volcanic events, ktore took place in the Solar System – said Carl Agee, one of the authors of theoin a publication.
The meteorite was found in the sands of Mauritania by a member of theoin the nomadic tribes living thereow. To the hands of Agee, whichory is considered a specialist in meteoritesow at the University of New Mexico came from a meteorite traderow. This one sent to the university probka of the rock, as he himself was not sure if it was actually a meteorite.
The meteorite named Northwest Africa (NWA) 11119 is brighter than most meteoritesow. Tridymite crystals are clearly visible insideow – mineral from the silicate clusterow. The professor gave a probka of the rock to his doctoral student to study it. Poorna Srinivasan analyzed the rock’s composition and mineralogy using m.in. computed tomography.
Srinivasan has determined that the silica-rich meteorite contains information that greatly expands scientific knowledge regarding the extent of volcanic rock composition during the first 3.5 millionoin the years of the formation of the Solar System.
– The mineralogy of this rock definitely rory differs from anything we have worked on before. One of the first things that drew attention to theocaught our attention were large silica crystals of tridymite, whichore are similar to the mineral quartz. When we conducted further image analysis to quantify the tridymite, we found that the amount present represented a staggering 30 percent of the total meteorite. Such a quantity is unprecedented in meteorites and poroThe amount present in someorych volcanic rocks on Earth – explained Srinivasan.
Part of Srinivasana’s research included roalso prob the discovery, by means of chemical and isotopic analyses, of what body the meteorite may have come from. She was only able to determine that it did not come from Earth.
– Based on the isotopes of oxygen, we know that it comes from a source ofoextraterrestrial source somewhere in the Solar System, but we can’t exactly locate it. However, thanks to measured isotopic values, we were able to link it to two other unusual meteorites – Northwest Africa 7235 and Almahata Sitta. The similarities between them suggest that they all come from the same parent body of. Perhaps it was a large, geologically complex body, ktore formed in the early Solar System – noted Srinivasan.
One possibility is that the parent object was hit by an asteroid and someore its fragments ejected into space eventually reached Earth. – The oxygen isotopes of NWA11119, NWA 7235 and Almahata Sitta are identical, but this gemstone – NWA 11119 – wyrosion as something completely different from all the more than 40,000 meteoritesow, whichore found on Earth,” said Srinivasan.
The researchers also determined the exact age of formation of the meteorite. Analyses have shown that NWA 11119 is about 4.5 billion years old.
– Most other magmatic meteorites known to usow has basaltic compositions, whichore have a much lower silica content. We wanted to understand how and when this unique meteorite formed in the crust of an asteroidal body in the early Solar System – said cooauthor of the publication Meenakshi Wadowa.
Most meteoritesow, whichore reach Earth, is formed by the collision of asteroids orbiting around theol of the Sun in an area called the asteroid belt located between the orbits of Mars and Jupiter. Asteroids, on the other hand, are remnants of the formation of the solar system some 4.6 billion years ago. The chemical composition of ancient magmatic meteoritesow is the key to understanding roThe diversity and geochemical evolution of the blockoIn the matter of whichorych the planets were formed.
– It is a meteorite unlike any other. Such meteorites were precursors to the formation of planets and represent a critical step in the evolution of rocky bodies in our solar system – explained another of the authorsoIn the publication, Daniel Dunlap.
– This research is key to understanding how planet-building blocks formed in the early Solar System. When we currently look at the solar system, we see fully formed bodies, planets, asteroids, comets and so on. Our curiosity pushes us to ask how they came to be? How the Earth was formed? It is basically the missing piece of the puzzle, whichor we have just discovered and ktora mowi us that these magmatic processes, functioning like small furnaces, melted rocks and processed all the objects of the Solar System – emphasized Agee.