The mysterious pieces of glass strewn across Chile’s Atacama Desert, and lined up in a vast corridor stretching 75 kilometers long, first came to the attention of scientists a decade ago. And it seems they have finally unraveled the mystery.
Researchers believe the place where the glass shards are found was the site of an ancient comet explosion about 12,000 years ago that exploded in Earth’s atmosphere, according to a new study published in the journal. Geology.
The old explosion would have produced an intense heat that turned the sandy soil of Atacama – at that time, the area was not a desert, and also had trees and grass – into vast areas of silicate glass, that is, a solid that contains silicon and oxygen in a particular structure.
The silicon glasses, some dark green and some black, are “twisted and folded” and have been found to stretch up to 50 centimeters wide, according to a statement from Brown University.
Remains of an alien object
The researchers noted that the shattered glass from the desert contains tiny mineral fragments commonly found in meteorites that land on Earth. Those minerals closely match the composition of material returned to Earth by NASA’s Stardust mission, which sampled the particles from a comet called Wild 2, according to the statement.
The team concludes that those mineral assemblages are likely the remains of an extraterrestrial object.
“This is the first time that we have clear evidence of glasses on Earth that were created by thermal radiation and winds from a fireball that exploded just above the surface,” said Pete Schultz, Professor Emeritus in the Department of Science. of the Earth, Environmental and Planetary from Brown University.
“Truly massive explosion”
A chemical analysis of the glass revealed the presence of zircons, or minerals that thermally decomposed to form baddeleyite crystals, a rare zirconium oxide mineral, according to the statement. That transition from zircon to baddeleyite typically occurs at temperatures above 1,670 degrees Celsius, which would definitely outweigh the heat generated by grass fires, according to the statement.
“To have such a dramatic effect on such a large area, this was a truly massive explosion. Many of us have seen fireballs from racing cars streaking through the sky, but those are miniscule compared to this,” he added.
The researchers estimated that the explosion occurred about 12,000 years ago, but hope that new studies will help pinpoint the date and size of the comet.
“It’s too early to say whether there was a causal connection or not, but what we can say is that this event happened around the same time we think the megafauna disappeared, which is intriguing,” Schultz said. “There is also the possibility that this was witnessed by the first inhabitants, who had just arrived in the region. It would have been quite a spectacle.”
Edited by Felipe Espinosa Wang.