Visit the right section of the desert along the Libyan and Egyptian border, and you can come across pieces of pale yellow glass, traces of impact of the meteorite 29 million years ago.
This glass, a remarkable piece of which was used in the jewelry found in Tutu's Tomb, it has long been claimed that there are heavenly roots. This is also the subject of a new study that finds that the so-called Libyan desert glass is probably created by a meteorite impact rather than a cosmic rock explosion. If the study persists, it suggests that scientists are learning threat of collisions of asteroids with the Earth you may not have to worry so much about the consequences of the place of large cosmic rocks that explode in the atmosphere.
"Both meteorite impacts and airborne explosions can cause melting," lead author Aaron Kavossi, a geologist at the University of Curtin in Australia, says a statement, "But meteorite impacts only create shock waves that form high-pressure minerals, so finding evidence of the former reidite confirms that it was created as a result of a meteor impact."
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They knew that whether the cosmic stone on the glass walls hit the ground or not, it was great. But Kawasaki and his co-author wanted to find out whether the culprit was an impact or an explosion. So they worked with seven pieces of pale yellow glass looking at them under a powerful scanning microscope. This allowed them to see closely crystalline zircon in the glass, which develop slightly different structures depending on what has happened to them over the millennia.
This analysis suggests that some of the crystals of the zircon have ever been reidite, a mineral formed only under very specific high pressure conditions that coincide with what happens when the meteorite strikes the Earth but not when it rock space explodes in the air. (In an email to Space.com, Cavosie added that although the scientists did not notice a crater to match the impact, there is a lot of sand in the area that can hide such a structure under the dunes.)
Kawasaki and his co-author hope that this is a comforting news for planetary defense experts who focus on the threat of crash of asteroids with the Earth and what people can do to defend themselves. That's because after air blast over Chelyabinsk, Russia in 2013people worried that Libyan desert glass was formed during a much larger air blast.
Now, geologists say that with the Libyan glass desert identified this scenario is off. Combine this with the fact that geologists have not found any evidence of relatively new mirror glass samples, and the findings show that even massive air blasts have not had such serious consequences on earth as some people feared.
The study is described in paper published on May 2 in the journal Geology.