On 27/09/2017 19:41, wrote:
"While they have not put forward an alternative explanation for the explosion, outlandish theories in the past have included a massive volcanic eruption, a comet mainly composed of ice not solid space rock, a black hole colliding with Earth and even aliens shooting down a meteor from a UFO in order to save Earth."

Mystery Deepens Over World's Biggest Explosion In Russia
Daily Mail - January 23, 2017
-- http://www.dailymail.co.uk/news/arti...on-Russia.html


What was so mysterious about the Chelyabinsk meteor ?
https://en.wikipedia.org/wiki/Chelyabinsk_meteor

I suppose they did not have dashboard cams 100 years ago for a slightly
larger meteor Earth-grazing air-burst event