Tunguska event
On the morning of 30 June 1908 an enormous explosion flattened forest over about 2,000 square kilometres in Siberia. No crater was ever found.
This butterfly-shaped pattern, with upright stripped trunks in the middle, is what an explosion several kilometres above the ground produces.
en.wikipedia.orgSuch proportions of metals are typical of meteoritic material.
en.wikipedia.orgThe glowing skies have been explained by dust and ice from a comet scattered in the upper atmosphere.
en.wikipedia.orgReports collected in the region describe a fireball travelling through the sky, which an eruption from the ground does not explain.
en.wikipedia.org