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Head lines F.R. Sarker, The Independent Between Jupiter and Mars, there is vast span of space where, according to astronomers some planet must have existed but instead millions of rocky chunks sizes ranging from a few inches to a few hundred miles are found, circling around the sun. Not only that, most of these objects like those of planets, rotate on its axis between 5 and 24 hours. These objects are called Asteroids. Astronomers believe that in the distant past, there was a solid planet orbiting through this space but some celestial accident caused it to break into pieces, which are now moving like ill-fated vagabonds. Ceres, the largest Asteroid is 623 miles across. Most of the asteroids are irregular and elongated in shapes and extremely black in colour with pock marks on its surface. Although these asteroids are moving around the sun through their respective orbits but there are some exceptional moments when they sidetrack their orbit and slam into the Earth. Scientists have calculated that during the history of our earth, millions of these asteroids have landed its surface. According to astrobiologists our life did emanate by the impacts of comets meteorites and asteroids which for million of years struck the earth bringing the amino acid, the building block of life from space which after a chain of synthesis, over billions of years, helped flourish life over this planet. Prior to the evolution of life and living organisms on earth, impacts of the asteroids was a boon as it was an essential metamorphosis but when life evolved full scale such impacts turned to be a bane as it threatened its existence. From time immemorial, thousands or millions of impacts by asteroids over the earth have taken place but mostly are unaccounted for due to changes over the anatomy of surface of earth by floods, dust storms, erosion, earthquakes, cyclones and lots of other natural calamities. However, astronomers have identified about 139 impact craters around the earth which, they believe were caused by the strike of asteroids. Among them the most spectacular is the bowl shaped Crater in Arizona, about 1 kilometer wide and 660 feet deep thought to be formed about 50,000 years ago. So far, the biggest impact crater created by asteroid lies beneath the marshy land of Chixulub, Mexico which is about 106 miles wide. Astrobiologist speculate that about 65 millions year ago, an asteroid 6 miles across slammed into the earth at a speed of 32,000 miles per hour over the Chixulub area which caused a devastating impact. For many months dust particles bounced over the earth's atmospheric belt, covered the sunlight creating an extremely frigid environment detrimental to the survival of the bigger species including Dinosaurs. Thus asteroids are blamed for extinction of Dinosaurs and some other species which once ruled the animal kingdom. On June 30, 1908 around late morning, people near Siberia, Russia, found a brilliant streak of light emanating from the sky suddenly dashed into the jungle of Tunguska. Within a few seconds a loud sound was heard following by a heavy jolt on the surface and people sitting on the chair as far as 70 miles away lifted off and fell down on the ground. Trans-Siberian trains running a few miles away derailed and the Richter scale in the observatories as far as Germany and the UK shot up their magnitude scales erratically. Later when a group of Russian scientists went to visit the impact area they found no trace of impact but all trees charred, uprooted and upside down stacked systematically within a few miles around the impact area. Scientists after thorough investigation reported that the intensity of the impact was about 12 million tons of TNT and 800 hundred times more powerful than the Nuclear bomb pounded by the U.S. forces over Hiroshima, Japan in 1945. Soon after Tunguska incident, astronomers around the started to feel that they might be the prey of the asteroid impact at any time but they were undone as no preventive measures could be made to save the earth and its people from its attacks. On January 17, 1991, astronomers in bigger observatories around the world noticed that an asteroid about 300 feet in diameter designated as 1991BA dashed towards earth but flew by at a distance of 106,000 miles from the earth about half the distance from earth to the moon. In 1995, Toutatis, a small asteroid came near to earth and some astronomers speculated that it might hit the earth but later it went away without causing any damage. On August 24, 2003, astronomers in Lincoln Near Earth Asteroid Research Programme (LINEAR) noticed that one asteroid around 1.2 kilometer wide, designated as 2003 QQ47 displayed a peculiar orbital parameter which after initial calculation they found it hurtling about 75,000 miles per hour and might strike the surface of the earth on August 24, 2014 with a destructive power of 360,000 TNT that is 8 million times greater than what was in Hiroshima by Atom bomb impact in 1945. This news was soon went to the British press and within hours entire world was jolted with the fear of this impending devastation. However, a revised version of the statement was later issued by the LINEAR which stated that the chances of impact is zero as such there is nothing to be worried of the celestial catastrophe in 2014. However, the wound caused by this frightening news would need long time to heal but people around the world are skeptical about the Revised Version of non-proliferation by 2003 QQ47 and fear would continue until that date is over. In 1998, western press made headlines with similar news that asteroid 1997 XFII would hit the earth in 2028. Whether astronomers assure or reassure that asteroids would not strike the earth in 2014 or in 2028 still the gamut is not out of danger. Evidences are there that over 1 kilometer wide asteroid hits the earth once in every half a million years and smaller sizes in 300 years , so the danger is still there to encounter the devastation caused by killer asteroids at any time . Of course, NASA has undertaken a project to keep the lists of the asteroids which are likely to be hitting the earth and already about 800 asteroids have been identified so far. Still there are some more which might come as a surprise, thus it has been crystal clear that the earth is quite vulnerable to be mauled by asteroids and the catastrophe might be regional as well as in global in parameter. NASA along with other organisations around the world are seriously trying to find out a solution to this volatile problem. One idea they have developed which is that as soon as any killer asteroid is detected heading towards earth, instantly a rocket would be sent to land on the surface of that asteroid. After landing on its surface, the wings will be unfurled and nuclear bombs to be blasted. As nuclear bombs has chain reaction and it creates jolts and jerks over a long time, which would help the direction of the asteroid, changed. Earth is only around 8000 miles in diameter. Any asteroid at a distance of 5 million miles, if a fraction of degree of angle is deviated, it would be enough to save the earth from its attack. But that plan is still in the realm of imagination and the practical application needs more time to be explored. The writer is General Secretary of the Bangladesh Astronomical Society |
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