El Ali meteorīta šķēle, kas tagad atrodas Albertas Universitātes meteorītu kolekcijā, satur divus minerālus, kas vēl nekad nav redzēti uz Zemes. Kredīts: Albertas Universitāte
Jauni minerāli, kas atklāti milzīgā meteorītā, var atklāt norādes uz asteroīdu veidošanos.
Pētnieku komanda 2020. gadā Somālijā atrastā 33 000 lb (15 000 kg) meteorītā ir atklājusi vismaz divus jaunus minerālus, kas uz Zemes nekad nav bijuši redzēti. Šis milzu meteorīts ir devītais lielākais, kāds jebkad atrasts.
“Kad atrodat jaunu minerālu, tas nozīmē, ka faktiskie ģeoloģiskie apstākļi, iežu ķīmija, atšķīrās no tiem, kas tika atrasti iepriekš,” saka Kriss Hērds, Zemes un atmosfēras zinātņu katedras profesors un Albertas kurators. meteorītu kolekcija. “Tas padara šo aizraujošu: šajā konkrētajā meteorītā jums ir divi oficiāli aprakstīti minerāli, kas zinātnē ir jauni.”
Viena 70 gramu smaga meteorīta šķēle tika nosūtīta klasifikācijai uz Albertas universitāti, kur tika atklāti abi minerāli. Šķiet, ka tiek izskatīts jau trešais minerāls. Hurds atzīmē, ka, ja pētnieki iegūs vairāk paraugu no masīvā meteorīta, pastāv iespēja, ka viņi atradīs vairāk minerālu.
Divus jaunatklātos minerālus nosauca par elaliītu un elkinstantonītu. Pirmais nosaukums elaliite cēlies no paša meteorīta, ko oficiāli sauc par “VisaugstākaisMeteorīts, jo tas tika atrasts netālu no Al-Ali pilsētas Somālijas Hieranas reģionā. Flock nosauca elkenstantonītu par otro minerālu pēc Lindija Elkinsa-Tantona, ASU Planētu iniciatīvas viceprezidenta, ASU Zemes un kosmosa izpētes koledžas profesora un pētījuma galvenā pētnieka.[{” 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.
