A multinational team of researchers led by academics from the University of Kent and Imperial College London has detected extraterrestrial particles in Antarctica, suggesting the continent was struck by an asteroid of medium size.
Particles were found on the peak of Walnumfjellet Mountain in Queen Maud Land, East Antarctica, where researchers estimate the collision happened around 430,000 years ago.
The found particles, known as condensation spherules, indicate that an asteroid with a diameter of at least 100 meters struck the ice at high speed 430,000 years ago. The collision triggered an explosion that ejected a jet of molten and vaporized meteor material, which dispersed and landed across the Antarctic ice sheet.
According to the authors of the research paper, this is a significant geological finding due to the scarcity of evidence for this sort of occurrence.
|The tiny particles discovered in Antarctica (Scott Peterson/micrometeorites.com)|
Matthew Genge, the co-author of the study, states that the explosion of a small asteroid or comet at a low altitude may be comparable to a nuclear explosion with energy estimated in megatons.
Asteroids that explode at low altitudes in the atmosphere are more common than those that cause craters, but they are the most difficult to detect in advance.
In this case, mountain debris was investigated by measuring exceedingly minute quantities of various chemical components.
Researchers detected a high nickel concentration and distinctive oxygen fingerprints in the debris, enabling them to estimate the impact date and emphasize the extraterrestrial origin of the retrieved articles.
Scientists on the team concur that the research emphasizes the need to reevaluate the danger presented by asteroids of medium size. This magnitude of impact would be very devastating across a broad region.
Reference(s): Imperial College London