The scientists probed the sample samples using transmission electron microscopy and discovered carbon grains that were finely veined with iron-based minerals including troilite, schreibersite and the iron–nickel alloy taenite, very similar to that in other iron-rich meteorites. Luckily, technology has evolved a great deal since then, and after taking a second, more thorough look, Ukranian researchers found that Kovalykh may have actually been right. Instead, what he had were terrestrial rocks altered by the high energy of the impact.
The grains also contained less of the dense metal iridium than is typically found in meteorites, so the scientific community concluded that Kovalykh’s samples weren’t actually from the meteor. Subsequent research by Kovalykh at the time revealed that the fragments contained a form of carbon called lonsdaleite, which has a crystal structure somewhere between graphite and diamond, and forms under extreme heat and pressure.
In 1978 Mykola Kovalyukh, an Ukranian scientist, collected fragments of rocks, less than one millimeter wide, from the epicenter of the impact site. Of course, the Soviets made a number of scientific expeditions in the area, but the best they could come up with were microscopic metallic spheres found in Tunguska soil samples, thought to be remnants of a vaporized meteorite, but these too are up for debate. Now, researchers in Ukrain led by Victor Kvasnytsya think they have finally sealed Tunguska. This is because the impact was so powerful that no fragments could be retrieved. In all likelihood, something that most geoscientists seem to agree upon, the even was triggered by a meteor impact, however some have proposed more extreme theories like antimatter and blackholes (yeah, blackholes…). It’s quite curious how the source of such an important event, in which an equivalent energy of 3 to 5 megatonnes of TNT was discharged, has been so difficult to confirm. (c) UNIVERSAL HISTORY ARCHIVE/GETTY IMAGESĪ recent study by scientists at the Institute of Geochemistry, Mineralogy and Ore Formation of the National Academy of Science of Ukraine in Kiev might settle the origin of the Tunguska event once and for all, after rock samples collected from a peat bog close to the epicentre of the blast bear uncanny physical characteristics found in other meteorites. Severed trees in the wake of the Tunguska alleged meteor impact. The leading theory is that a meteor exploding in the atmosphere caused the huge blast, however up until now this has been difficult to confirm despite being the likeliest option. More than a century since, its remarkable that scientists have yet to confirm the source of what undoubtedly is the biggest Earth impact in recorded history. You may have heard about the Tunguska event – a huge blast of energy which occurred in 1908 over Russia and flattened more than 2,000 square kilometres of forest.
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