Dois minerais – nunca antes vistos na Terra – foram descobertos em um enorme meteorito

Novos minerais descobertos em um meteorito maciço podem revelar pistas para a formação de asteroides.

Uma equipe de pesquisadores descobriu pelo menos dois novos minerais nunca antes vistos na Terra em um meteorito de 33.000 libras (15.000 kg) encontrado na Somália em 2020. Este meteorito gigante é o nono maior já encontrado.

“Quando você encontra um novo mineral, isso significa que as condições geológicas reais, a química das rochas, eram diferentes do que foi encontrado antes”, diz Chris Hurd, professor do Departamento de Ciências da Terra e Atmosféricas e curador do meteorito de Alberta. coleção. “É isso que torna isso emocionante: neste meteorito em particular, você tem dois minerais oficialmente descritos que são novos para a ciência”.

Uma fatia de 70 gramas do meteorito foi enviada à Universidade de Alberta para classificação, onde os dois minerais foram descobertos. Parece que já existe um possível terceiro mineral em estudo. Hurd observa que, se os pesquisadores obtiverem mais amostras do enorme meteorito, há uma chance de encontrarem mais minerais.

Os dois minerais recém-descobertos foram nomeados elaliita e elkinstantonita. O primeiro nome, elaliita, vem do próprio meteorito, que é oficialmente chamado de “Mais altaUm meteorito porque foi encontrado perto da cidade de Al-Ali, na região de Hiran, na Somália. Flock nomeou a elkenstantonita como o segundo mineral depois de Lindy Elkins-Tanton, vice-presidente da Iniciativa Planetária da Arizona State University, professora da Faculdade de Exploração da Terra e do Espaço da ASU e investigadora principal do[{” attribute=””>NASA’s upcoming Psyche mission.

A slice of the El Ali meteorite contains two minerals never before seen on Earth. Credit: University of Alberta

“Lindy has done a lot of work on how the cores of planets form, how these iron-nickel cores form, and the closest analogue we have are iron meteorites. So it made sense to name a mineral after her and recognize her contributions to science,” Herd explains.

In collaboration with researchers at the University of California, Los Angeles (UCLA) and the California Institute of Technology (Caltech), Herd classified the El Ali meteorite as an “Iron, IAB complex” meteorite, one of over 350 in that particular category.

As Herd was analyzing the meteorite to classify it, he saw something that caught his attention. He brought in the expertise of Andrew Locock, head of the University of Alberta’s Electron Microprobe Laboratory, who has been involved in other new mineral descriptions including Heamanite-(Ce).

“The very first day he did some analyses, he said, ‘You’ve got at least two new minerals in there,’” says Herd. “That was phenomenal. Most of the time it takes a lot more work than that to say there’s a new mineral.”

Locock’s rapid identification was possible because the two minerals had been synthetically created before, so he was able to match the composition of the newly discovered natural minerals with their human-made counterparts.

Scientists are still examining the minerals in detail to determine what they can tell us about the conditions in the meteorite when it formed.

“That’s my expertise — how you tease out the geologic processes and the geologic history of the asteroid this rock was once part of,” says Herd. “I never thought I’d be involved in describing brand new minerals just by virtue of working on a meteorite.”

Herd also notes that any new mineral discoveries could possibly yield exciting new uses down the line.

“Whenever there’s a new material that’s known, material scientists are interested too because of the potential uses in a wide range of things in society.”

While the future of the meteorite remains uncertain, Herd says the researchers have received news that it appears to have been moved to China in search of a potential buyer. It remains to be seen whether additional samples will be available for scientific purposes.

Herd described the findings at the Space Exploration Symposium on November 21 at the University of Alberta’s ETLC Solarium.