Customer Reviews

Cosmic Travelers - Comets and Asteroids [VHS]

5 star:		(0)
4 star:		(1)
3 star:		(0)
2 star:		(0)
1 star:		(0)

 

 

While this tape is a bit alarmist in raising the issue of the potential of a deadly strike of Earth by a comet or asteroid, it is not over the top. There is no question that there is the threat that human life on Earth will be extinguished by a comet or asteroid striking the Earth. The point of dispute is the probability of such an event, which is very difficult to compute. Clearly, such a catastrophic strike is extremely unlikely, although the probability of a powerful, non-catastrophic strike is much higher.
To understand this, it is only necessary to refer back to the event known as the Tunguska explosion in 1908. With no warning, a comet or an asteroid exploded in the atmosphere above Siberia, destroying over 80 million trees in an area of approximately 830 square miles. Had this explosion occurred over a populated area, the death toll could have easily been in the millions and the size of the asteroid has been estimated as less than 100 meters in diameter. Clearly, the destruction wrought by a larger body would be far greater.
Few non-astronomers realize that only a small percentage of the sky is subject to regular surveillance. Therefore, it is possible for an astronomical body to approach the Earth undetected. For this reason, there is a movement to create a group whose purpose is to scan the entire heavens in a search for potential dangers. In conjunction with this effort, some form of intervention mechanism to deflect any dangerous bodies would also have to be developed.
All of this is explained in this tape with only an occasional descent into needless hype. It is a good survey of the potential danger as well as a brief recapitulation of what has happened in the past, both recent and distant.