An asteroid skimmed the Earth at a low altitude above Siberia in June 30, 1908, causing an explosion that was 2,150 square kilometers (km2) wide.
Known as the Tunguska event, it was the "most explosive meteor impact on record," according to the Daily Mail. It produced a shockwave that flattened over 80 million trees, which set the Russian forest alight.
The Daily Mail said the explosion was so strong that "Air waves from the blast were detected as far away as the UK and Washington DC in the US, as well as Germany, Denmark, Croatia, and Indonesia."
Russian scientists were surprised to not find an impact crater or space rocks on the ground where the explosion occurred.
Shockwave
The Daily Mail said, "the explosion was a shock wave from the asteroid's trajectory rather than an impact." This explained the explosion's lack of evidence, despite being so cataclysmic
An iron asteroid reportedly disintegrated 9.66 kilometers above the ground before going back to space, losing over half of its weight on its journey back.
The study was published in the Monthly Notices of the Royal Astronomical Society. It said the researchers "argue that the Tunguska event was caused by an iron asteroid body, which passed through the Earth's atmosphere and continued to the near-solar orbit."
The asteroid had a peak altitude of 15 km and traveled at 20 km per second. The scientists said there were optical effects at play, which is "associated with a strong dustiness of high layers of the atmosphere over Europe," said the Daily Mail. This caused the night sky to glow.
Scientists said the shockwave could have been caused by high-temperature plasma emitted rapidly as the asteroid approached Earth.
There were even theories suggesting the rock may have been made from stone or water ice. Both were disproven by scientists, saying they would have fallen apart due to pressure and heat.
No evidence left behind
The Daily Mail said, "the theory that the Tunguska space object consisted of iron would explain why there are no iron droplets at the epicenter - they wouldn't have reached the planet's surface because of its immense speed."
Iron would have explained why the night sky glowed even in America.
However, there were sediments found in Lake Zapovednoye, 40 km away from the epicenter of the explosion. These contained potassium, titanium, rubidium, yttrium, and zirconium -all of them are related to the Tunguska Explosion, researchers said.
According to Dr. Arthur Meidus, who is a deputy director of a nature reserve, said, "'We discovered a distinguishing light-colored layer in sediments of Lake Zapovednoye. This way we know which layer of sediments might contain particles of extraterrestrial origin."
If they prove some of the sediment samples are out of this world, they could prove that Tunguska truly happened.
