About 430,000 years ago, a meteorite exploded over Antarctica. We know this because a team of international space scientists, led by researcher Matthias van Ginneken from the School of Physical Sciences at the University of Kent, has found new evidence of a low-altitude meteoric landing that reached the Antarctic ice sheet in this moment.
Extraterrestrial particles (condensation spherules) have been recovered atop Walnumfjellet within the Sør Rondane Mountains in East Antarctica and indicate an unusual landing event of an asteroid at least 100 meters in diameter that reached the surface at large velocity. Their chemistry and high nickel content suggested they originated in outer space. It was not powerful enough to create an impact crater, but it was not light either , as the researchers believe that the jet of molten and vaporized material that was expelled from the explosion would have been more dangerous than the Tunguska event that devastated a Siberian forest. back in 1908.
The findings highlight the importance of reassessing the threat from medium-size asteroids, with the potential for “destructive ” consequences, the authors explain in their study published in the journal Science Advances.
Experts collected the 17 dark black particles, all less than 1 millimeter and invisible to the naked eye, during an expedition to these mountains where the Belgian Princess Elisabeth Antarctica station is based.
“I noticed for the first time that some of them seemed to be stuck together, which should have happened when they were melted. It would have meant that many of them interacted with each other when they were at a very high temperature. The only sensible way to explain this was a big shock, ”says van Ginneken.
This type of explosion caused by the impact of a single asteroid is described as intermediate , since it is larger than an explosion in the air, but smaller than an impact crater event.
“To complete the asteroid impact record on Earth, we recommend that future studies focus on identifying similar events on different targets, such as rocky or shallow ocean basements, as the Antarctic ice sheet only covers 9%. of the Earth’s surface. Our research may also be useful for identifying these events in deep-sea sediment cores and, if plume expansion reaches land masses, the sedimentary record. While landing events may not threaten human activity if they occur over Antarctica, if they occurred over a densely populated area, it would cause millions of casualties and serious damage over distances of up to hundreds of kilometers. ‘ ‘
Referencia: The research paper ‘A large meteoritic event over Antarctica ca. 430 ka ago inferred from chondritic spherules from the Sør Rondane Mountains’ (M. van Ginneken – University of Kent; S. Goderis, F. Van Maldeghem, P. Claeys, B. Soens – Vrije Universiteit Brussel; N. Artemieva – Planetary Science Institute and Russian Academy of Sciences; V. Debaille – Université Libre de Bruxelles; S. Decrée – Belgian Geological Survey and Royal Belgian Institute of Natural Sciences; R. P. Harvey, K. Huwig – Case Western Reserve University; L. Hecht – Museum für Naturkunde Berlin and Freie Universit.t Berlin; F. E. D. Kaufmann – Museum für Naturkunde Berlin; S. Yang, M. Humayun – National High Magnetic Field Laboratory and Department of Earth; M. J. Genge – Imperial College London) is published by Science Advances. doi: 10.1126/sciadv.abc1008
