New Paper Has a Wild Explanation For The Most Explosive 'Meteor Impact' on Record
MICHELLE STARR - 5 MAY 2020
In the early morning of 30 June 1908, something exploded over Siberia. The event shattered the normal stillness of the sparsely populated taiga, so powerful that it flattened an area of forest 2,150 square kilometres (830 square miles) in size - felling an estimated 80 million trees.
Eyewitness reports describe a brilliant ball of light, shattered windows and falling plaster, and a deafening detonation not far from the local river. The Tunguska event - as it came to be known - was later characterised as an exploding meteor, or bolide, up to 30 megatons, at an altitude of 10 to 15 kilometres (6.2 to 9.3 miles).
It is often referred to as the "largest impact event in recorded history", even though no impact crater was found. Later searches have turned up fragments of rock that could be meteoric in origin, but the event still has a looming question mark. Was it really a bolide? And if it wasn't, what could it be?
Well, it's possible we'll never actually know… but according to a recent peer-reviewed paper, a large iron asteroid entering Earth's atmosphere and skimming the planet at a relatively low altitude before flying back into space could have produced the effects of the Tunguska event by producing a shock wave that devastated the surface.
"We have studied the conditions of through passage of asteroids with diameters 200, 100, and 50 metres, consisting of three types of materials - iron, stone, and water ice, across the Earth's atmosphere with a minimum trajectory altitude in the range 10 to 15 kilometres," wrote researchers led by astronomer Daniil Khrennikov of the Siberian Federal University in their paper.
More:
https://www.sciencealert.com/scientists-have-a-new-theory-about-the-colossal-tunguska-event-explosion