© Leonid Kulik Expedition, WikipediaTunguska: The Largest Recent Impact Event
This Monday 27th June 2011 a small asteroid will pass within 8,000 miles of the Earth, a mere hair's breadth by astronomical standards.
NASA's Near Earth Object Observation Programme though is on the watch for those objects that threaten to actually collide with our planet. Their aim is to detect these threats as far ahead as possible, leaving us many years, if not decades or more, to work out how to prevent any collision.
This month 103 years ago a large comet entered the atmosphere and caused an air burst over Podkamennaya Tunguska River, Siberia. As a result some 80 million trees were flattened. The trees nearest the epicentre were still standing but stripped as bare as telephone poles. Although no-one was reported to have died in this event in such a remote area, hundreds of the reindeer the locals relied on for their livelihood were killed.
At the time the locals thought that they had been cursed by the god Ogdy and their reluctance to talk about it together with difficulties getting to the region meant that it took many years for investigators to find out what had happened. The first scientific team led by Leonid Kulik of the St Petersburg museum did not get to the area for 19 years.
According to NASA the asteroid, which weighed in at 220 million pounds, hit the Earth's atmosphere at 33,500 mph. The asteroid caused the air to heat to 44,500 degrees Fahrenheit and the asteroid released the energy equivalent of 185 Hiroshima 'Little Boy' bombs (this figure varies depending on which source you look at). The Little Boy yielded the equivalent of 13-18 kilotons of TNT.
The asteroid did not actually hit the earth, but it disintegrated with such force that it flattened 20,000 square kilometres of woodland.
So next time you hear politicians warning about how critical a few banks are just give this a thought.
stock up on peanut butter, its nutritious, and can last unspoiled ten years if unopened