Ameteor that explodedover Antarctica around 430,000 years ago was “ completely destructive over a expectant area ” , according to a new study document the discovery of 17 particles forget over from the flak . Recovered from the peak of a mountain called Walnumfjellet , the rare fragments indicate that thespace rockmust have been at least 100 meter ( 330 ft ) in diam , and collided with the ground at gamy speed .
What ’s rum about this event , however , is that the meteoroid in question was not great enough to leave an impact crater , yet was sufficiently bulky to reach the Earth without simply burning up in the atmosphere . report their determination in the journalScience onward motion , the subject author describe the impact as a rare “ medium touchdown event ” , in which a “ jet-propelled plane of melt and vaporise meteoritic material ” was able-bodied to reach the surface , stimulate serious damage but lacking the tightness required to generate acrater .
The find of the particles is something of a wonder in itself , given that the big was less than half a millimeter in size . Using scanning electron microscopy , the research worker find oneself the fragment to be made up of mostly iron and olivine , with high nickel contentedness . This matches the composition of certain meteorites , confirming that the particles were of redundant - sublunary origin .
The midget piece of space rock’n’roll also contained oxygen isotopes that are characteristic of Antarctic shabu , hint that they obtained these upon shock with the Earth’s surface , rather than by burning up in the atmosphere . This implies that when themeteorite blow up , vaporized material was sent cast to the solid ground at high speed , where it condensed as it meld with the Antarctic trash sheet .
What ’s more , the result condensation spherules were found to be extremely like in their chemic composition to spherule left over from two other touchdown events that come over Antarctica around 430,000 years ago . Based on this observance , the researchers job that these particles were all produced by the same exploding asteroid , suggesting that the wallop post out a plume of debris that span a Brobdingnagian area .
As such , the subject area authors reason out that meteoritic explosions of this size have the potential to engender blast effect induce unassailable overpressure over field up to 100,000 square klick ( 38,610 square miles ) , while also produce enough caloric radiation to spark fires over an region of 10 to 1,000 straight kilometers ( 3.86 to 386.1 square mi ) across-the-board .
In astatement , cogitation author Matthias van Ginneken explain that “ while touchdown events may not threaten human bodily process if occurring over Antarctica , if it was to take place above a densely populated area , it would result in million of casualty and severe damage over distances of up to hundreds of klick . ”
