Dua mineral – belum pernah terlihat di Bumi – ditemukan di meteorit masif

Mineral baru yang ditemukan di meteorit masif dapat memberikan petunjuk pembentukan asteroid.

Setidaknya dua mineral baru yang belum pernah terlihat sebelumnya di Bumi telah ditemukan oleh tim peneliti dalam meteorit seberat 33.000 pon (15.000 kg) yang ditemukan di Somalia pada tahun 2020. Meteorit besar ini adalah yang terbesar kesembilan yang pernah ditemukan.

“Setiap kali Anda menemukan mineral baru, itu berarti kondisi geologis yang sebenarnya, kimia batuan, berbeda dari sebelumnya,” kata Chris Herd, profesor di Departemen Ilmu Bumi & Atmosfer dan kurator koleksi meteorit Universitas Alberta. . “Itulah hal yang menarik: Dalam meteorit khusus ini, Anda memiliki dua mineral yang dijelaskan secara resmi yang baru bagi sains.”

Sepotong meteorit seberat 70 gram dikirim ke Universitas Alberta untuk klasifikasi, tempat kedua mineral itu ditemukan. Tampaknya sudah mempertimbangkan mineral ketiga yang potensial. Herd mencatat bahwa jika peneliti mendapatkan lebih banyak sampel dari meteorit masif, ada kemungkinan lebih banyak mineral akan ditemukan.

Dua mineral yang baru ditemukan diberi nama elaliite dan elkinstantonite. Nama depan, Elaliit, berasal dari meteorit itu sendiri, yang secara resmi dikenal sebagai “El Ali“Meteorit karena ditemukan di dekat kota El Ali di wilayah Hiiraan Somalia. Herd menamai mineral kedua, elkinstantonite, setelah Lindy Elkins-Tanton, wakil presiden Prakarsa Antarplanet ASU, profesor di Sekolah Eksplorasi Bumi dan Luar Angkasa Arizona State University, dan peneliti utama[{” 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.