Dois minerais – nunca antes vistos na Terra – descobertos em meteorito maciço
Disco de meteorito El Ali

Uma fatia do meteorito El Ali agora preservada na coleção de meteoritos da Universidade de Alberta contém dois minerais nunca antes vistos na Terra. Crédito da foto: Universidade de Alberta

Novos minerais descobertos em meteoritos maciços podem fornecer pistas para a formação de asteroides.

Pelo menos dois novos minerais nunca vistos antes na Terra foram descobertos por uma equipe de pesquisadores em um meteorito de 33.000 libras (15.000 kg) encontrado na Somália em 2020. Este enorme meteorito é o nono maior já encontrado.

“Sempre que você encontra um novo mineral, significa que as condições geológicas reais, a química da rocha, eram diferentes de antes”, diz Chris Herd, professor do Departamento de Ciências da Terra e Atmosféricas e curador da Coleção de Meteoritos da Universidade de Alberta. . “Isso é emocionante: neste meteorito em particular, você tem dois minerais oficialmente descritos que são novos para a ciência”.

Uma única fatia de 70 gramas do meteorito foi enviada para a Universidade de Alberta para classificação, onde os dois minerais foram descobertos. Já parece estar considerando um potencial terceiro mineral. Herd observa que, se os pesquisadores obtivessem mais amostras do enorme meteorito, há uma chance de que ainda mais minerais sejam encontrados.

Os dois minerais recém-descobertos foram nomeados elaliita e elkinstantonita. O primeiro nome, Elaliit, vem do próprio meteorito, oficialmente conhecido como “El Ali“Meteorito porque foi encontrado perto da cidade de El Ali, na região de Hiiraan, na Somália. Herd nomeou o segundo mineral, elkinstantonita, em homenagem a Lindy Elkins-Tanton, vice-presidente da ASU Interplanetary Initiative, professora da Escola de Exploração da Terra e do Espaço da Arizona State University e investigadora principal do[{” attribute=””>NASA’s upcoming Psyche mission.

El Ali Meteorite

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.

By Gabriel Ana

"Passionate student. Twitter nerd. Avid bacon addict. Typical troublemaker. Thinker. Webaholic. Entrepreneur."

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