Saturday, December 4

The comet that melted 80 kilometers of desert in a huge crystal field

San Andrés de Pica is a small town of 4,000 inhabitants in the heart of the Chilean Great North. Around it, protected by one of the driest climates on the planet, there are rare fragments of silicate glass that have intrigued scientists for decades. For those huge, twisted-shaped crystals to be there, scattered in the middle of the desert, they would need to have reached truly hellish temperatures, but how was that possible?

Desperate, scientists came to believe that the crystallization of the soil had been produced by huge fires that affected the region before it became desert. However, that did not convince everyone. Now a team from Brown University and Chile’s National Geology and Mining Service has analyzed the composition of the crystals and has arrived to a truly spectacular conclusion: are the remains of a meteorite impact.

Hell on earth

12,000 years ago, a comet entered the atmosphere directly to the very center of the Atacama area and just when it touched the densest layers of the atmosphere, the friction of the moment heated it up so much that it caused an explosion so large that it woke up. a fury of fire, temperature and hurricane-force winds that melted 80 kilometers of Chilean territory.

There they were preserved for millennia until, upon arrival at the researchers’ laboratory, it was clear that it could not be a matter of a forest fire. There was troilite and cubanite, minerals from space rocks. “Those minerals are [precisamente] those who tell us that this object has all the markings of a comet“explained Scott Harris, planetary geologist and co-author of the study.” Have the same mineralogy that we saw in the samples of [la misión] Stardust contained in these crystals is really powerful evidence that what we are seeing is the result “of a comet outburst.

In fact, it is quite possible that the same meteorite created the conditions that have allowed the good conservation of the glass fragments. It is still too early to say, but the temporal coincidence seems to indicate that the same explosion was the one that wiped out the megafauna in the area. A megafauna that has no longer recovered. However, my favorite coincidence is not that: but, according to the available data, at that time there were already human beings in that area of ​​Chile. Could they see, even from afar, how the world burned in a matter of seconds?

Image | Diego Jimenez