Posted June 27, 2013
A column of blue light shot across the sky. A few Russians saw it and wondered what on earth it could be.
(Hint: it wasn't ON Earth.)
A boom and a flash, and a shock wave that knocked people off their feet. Windows broke.
Luckily for those people, they were really far away from the explosion. The living things nearby weren't so lucky: 80 MILLION trees were knocked down! The felled trees were arranged in a circular pattern with the an epicenter near the Podkamennaya Tunguska River, in Russia.
What caused this huge explosion, which happened on this date in 1908?
Scientists believe that the Tunguska event was an “airburst” of a large meteoroid or comet. It was rushing toward the Earth at great speeds and began to burn up in our atmosphere. When it was three to six miles (5 – 10 km) away from Earth's surface, apparently, the meteoroid or comet got so hot it exploded. It was the shock wave from this explosion—basically, the air that was pushed strongly and rapidly away from the exploding body—that caused the trees to fall.
Even though the meteoroid or comet burst in the air rather than hit the Earth's surface, this event is still referred to as a meteor (or comet) impact. As a matter fact, it is the largest impact event on Earth in recorded history. The explosion was about a thousand times more powerful than the atomic bomb dropped on Hiroshima, Japan.
If the event had happened in a populated area, it would have destroyed an entire city!
Partly because of this event, many people are working on a way to protect ourselves from other, possibly even larger meteoroid, asteroid, and comet impacts. Read about “laser bees” here, the Don Quijote plan here, and paintball planetary protection here!
Also on this date:
Did you hear that Nik Wallenda crossed Niagara Falls on Friday, June 15, 2012, for the first time in history? Well, Wallenda's crossing was at the widest, wildest, wettest spot. This 1859 crossing (by a guy named Gravelet) was a lot tamer because it was higher up on the river. (But Gravelet later crossed the Falls on a tightrope while blindfolded, then while pushing a wheelbarrow, then on stilts, and then while carrying another man!!!)