An impressive experience

One ordinary morning in June, a man in Russia sat on the porch outside
his house reading the newspaper. The weather was clear and the air was
fresh. One could hear the chirping of birds. The sun was still rising
in the east.

After a while, he finished the newspaper, put it down and looked up.
That's when a bright light fell from the sky in the north. It didn't
look like anything he had ever seen before. There was no sound, and he
remembered thinking that the sight was strangely beautiful.

The light grew and spread, soon covering the whole northern sky like a
fire. He could feel the immense heat, as if his shirt were on fire. He
began to wonder if he should take it off.

Then the shock wave hit him. His earsdrums were blown out by the massive
air pressure, and he was physically lifted from the ground by the
enormous gush of air. He lost consciousness. When he awoke, he found
himself some meters from his porch. His wife ran out and helped him
inside. His clothes were torn and his house was slightly damaged, but by
a stroke of luck he himself was largely unharmed.

The trees and animals closer to the site of the explosion were not so
fortunate. Two thousand square miles of forest were simply knocked over,
lying on the ground pointing away from the epicenter like big wooden
arrows. Some things directly under the explosion simply evaporated from
the heat. The place where this happened is called Tunguska, and the year
was 1908.

What was it that caused the explosion in Tunguska? Even today, that is
subject to some debate. However, the most probable theory is that it was
caused by a large rock entering the Earth's atmosphere at high speed,
exploding some kilometers above Earth's surface. Outer space is full of
rocks and debris, any of which might be on a collision course with Earth.
The majority of the advanced weapons humanity has used on itself is no
match for a high-speed projectile.

The event in Tunguska over a hundred years ago is what I consider to be
 an impressive event. It makes us realize how small, powerless and
exposed we all are on this planet. Perhaps it can also make us grateful
that such catastrophes are as rare as they are.