They analyzed the samples with traditional microscopy techniques, mass spectrometry and high-powered X-rays-techniques that have been developed and refined in the past few decades-to give a much more detailed view, and published their findings in Planetary and Space Science in May. Image courtesy of Kvasnytsya et al./Planetary and Space Science Taking a Closer LookĪrmed with new and improved scanning technology, a group of geologists from Europe and North America decided to resurrect these mineral samples from their archive in the Ukrainian Academy of Sciences. Zooming in on the structure and composition of the Tunguska mineral samples. But these samples could also have formed when the heat and pressure of the space blast encountered rocks right here on our home planet, so the results were deemed inconclusive. The amount of pressure required to form such samples suggested that the minerals were contained in a meteorite that smacked into the Earth. Researchers determined the samples to be 99.5 percent carbon with inclusions of other trace elements such as troilite and iridium. A 1978 expedition came closer when it uncovered minuscule mineral samples embedded in peat at the epicenter of the blast. The comet hypothesis was gaining traction by mid-century since such a mass of ice and dust would have vaporized when it hit the Earth's atmosphere, causing an explosion without leaving any physical trace. But with so little evidence to go on, none of the theories could be proven. Scientific expeditions over the last century have combed the site and proposed a flurry of hypotheses: some said meteoroid some said comet. Over a century later, it is still the largest impact event in Earth's recorded history. The area was uninhabited (luckily) but that did not mean the blazing ball of who-knows-what went unnoticed. The burning chunk of rock struck Siberia on Jwith a force 1,000 times more powerful than the atomic bomb dropped on Hiroshima. It has taken researchers over a century to identify the extraterrestrial object-but in a recent paper, geoscientists revealed that the culprit was indeed a meteoroid. But whatever it was, scientists found no trace of it in the charred rubble.
On this day 105 years ago, Russians were reeling from the enormous fireball that streaked through the sky the day before and flattened almost 800 square miles of trees near the Podkamennaya Tunguska River. Previous studies had suggested the Tunguska object was made of ice or rock.Damage from the 1908 Tunguska impact as documented by Leonid Kulik on his 1929 expedition to the epicenter. "The results support our explanation of one of the long-standing problems of astronomy - the Tunguska phenomenon, which has not received reasonable and comprehensive interpretations to date", researchers wrote. It likely flew 3,000km (1,800 miles) through Earth's atmosphere at an eye-watering 11.2km per second (seven miles per second).Īn explosion occurred no lower than 11km (seven miles) above Earth's surface, according to the paper. However rather than being made mostly of rock, a comet contains lots of ice and gas, which can result in amazing tails forming behind them (thanks to the ice and dust vapourising)
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