Biodiversity - what if a meteor hits the Earth?
September 5, 2006 1:51am CST
NASA says there is an asteroid (Forget, for the time being, the new definition of planets, other heavenly bodies or even about the number of planets in the Solar system and prepare ourselves for the future) that is likely to hit the earth in 2029 and again in 2036. As people concerned with life sciences, we are definitely worried. Past changes in the global climate, caused by whatever means, have resulted in major shifts in species ranges and marked reorganization of biological communities. No one knows the size, composition, speed or the direction of the asteroid and so the kind of impact it will have upon hitting the Earth is difficult to determine.We are still to learn conclusively the total effect of the meteor that fell 65 mullion years ago. What we definitely know is that this deadly impact that caused the extinction of the dinosaurs was not as devastating as the one that impacted the Earth 251 million years ago -The Great Dyeing- that killed 90 % of the population.However, we have some a long way from those days. Today we have technologies that can detect the coming dangers and, if necessary fire missiles or use other means to disintegrate it. Recent studies reveal that noise level in the oceans today is 10 times more than what it was 50 years ago. Noise does affect life genetically but the process of evolution continues, nevertheless. Sea creatures will adapt themselves to life at this noise, waste pollution and water movement levels. Another factor we are aware of is that global warming will cause crops to grow at places, which are too cold presently to drying-up crops at some of the fertile lands and thus affect biodiversity (Not necessarily adverse effect only).Let us remember that the current levels of human impact on biodiversity are unprecedented, affecting the planet as a whole, and causing large-scale loss of biodiversity. Current rates and magnitude of species extinction, related to human activities, far exceed normal natural rates Some of us are aware the meteor that hit the Yucatan Peninsula in Mexico 65 million years ago was 50 thousand times more powerful than the one dropped on Hiroshima. As recent as 1994, Shoemaker Levy 9 hit Jupiter with the energy of 50 million Hiroshima-type bombs. If a large meteor were to hit the Earth, the kind of Shoemaker Levi 9, the impact is difficult to work out. Studies show that meteors with impact of 300 Hiroshima type bombs are 1% every year. US is contemplating monitoring the impact of meteors and comets near Earth. Scientists believe that the small rocks (meteors) hitting the ground are generally poor conductors of heat. Their central region remains cool even as the hot outer layers get ablated away while entering the atmosphere and before hitting the ground. Let's not forget that this method is copied while designing spaceships for reentry. Astronomers say that the meteors should be barely warm or even cool when they hit the ground. Let's hope the scientific community is right in its appraisal that there is no cause for worry, and that natural evolution and adaptation will go on. Meteors as such are no threat to biodiversity. No special survival techniques are needed. It would be exciting to witness a falling meteor but life will go on. People have been HAPPILY living with the warning of cataclysm posed by accelerated global warming for over 25 years.I invite all discussion group members to comment upon this posting.