Within seconds a century ago, at 7:14 a.m. on 30 June 1908, something destroyed 80 million trees. And not a single environmentalist protested. There were no environmentalists in the modern sense. Scientists and seers started theories on what caused greatest explosion in recorded history.
They are still arguing over just what exploded 33,000 feet above a remote part of central Siberia near the Tunguska River.
What is beyond doubt is the damage. The devastation extended over 1,500 square miles. The shock wave was felt over 600 miles away. Much closer, perhaps 10 miles for the epicenter, a party of reindeer herdsmen was hurled from their tents. Small fires sprang up in the surrounding forest. One of the men died from his injuries.
Despite the very best explanations offered by alien enthusiasts, flying crockery crackpots and assorted other pseudo-scientists, qualified experts are convinced it was an inbound near-earth object (NEO). In other words, a comet or an asteroid – said scientists are still not sure which.
While the NEO made a mighty bang, it did not release quite as much energy as was previously thought. More studies of the area affected showed the trees were diseased and the landform tended to concentrate the force. Still, the explosion would have measured three to five megatons, according to recent research using a new supercomputer.
The nuclear bomb dropped on Hiroshima, Japan, in August 1945, was measured at 13 kilotons. A stony asteroid a mere 100-feet in diameter could have accounted for the Tunguska devastation.
Much bigger meteorites have hit Canada in the past – much, much bigger and, fortunately for us, many, many millions of years ago. One hitting where Sudbury now stands left a crater 125 miles across as well as the mineral riches mined there today. The largest crater still visible from the air anywhere on Earth’s surface is that of Manicouagan in northern Quebec.
These, and other elsewhere, were made by space objects reaching the planet’s surface, resulting in impact craters. The asteroid or comet that caused the Tunguska event exploded in the lower stratosphere, leaving no crater discovered yet and some very puzzled pundits.
Has anything bigger ever hit here? Look at the map of Canada and observe the southeast end of Hudson Bay. It looks as if a giant has taken a bite out of the Quebec shoreline. Some people, including Canadian author Farley Mowat, have speculated that this is the edge of yet another impact crater.
So why worry? Because, say researchers at the University of Western Ontario, it will happen again. Not could. Will. Their estimate if time for a Tunguska-size event is every 200 to 1,000 years. Of course such an NEO might impact anywhere. But think what it would do to Ottawa. Or Toronto.
Canada will commence the search in a couple of years for such intruders on our lebensraum. The Near Earth Object Surveillance Satellite (NEOSSat) is a 60-kilogram satellite, worth $10-million but so technologically advanced it will make us the world leader in such matters. This time, if something eradicates our landscaping, at least we may know it’s coming.
