Introduction
In this paper, the topic “The odds and consequences of the Earth being hit by an asteroid or a large meteor” is going to discussed. This is a very important topic since it is imperative for the astronomers as well as the general public to be aware of the chances of the Earth being hit and the consequences that may follow in order to take the necessary measures.
There is going to be a general discussion about the asteroids and meteors and this will be followed by a discussion about the consequences of the Earth being hit by an asteroid or a larger meteor. There is also going to be a discussion about the chances of the Earth being hit and how to deal with this threat. In the conclusion section, a summary of the discussion is going to be given.
Asteroids and Meteors
An asteroid is a lump of rock which moves around the sun. The asteroids are sometimes referred to as minor planets. A large number of asteroids move around the sun in a wide band between the planets Mar and Jupiter, referred to as the asteroid belt. This belt is about two hundred and fifteen million miles wide. The asteroids are pieces that were left behind after formation of the planets from rocks. Among the asteroids, there are those that travel outside the asteroid belt and move out toward the planet Saturn or in toward the planet Earth (Kindersley, 2007).
On the other hand, the meteors are mostly sand grain sized rock pieces which travel in space at a speed of up to hundreds of kilometers per second. When they get into the atmosphere of the earth, they burn up and subsequently create bright flashes across the sky (What are meteors, 2011). Most of them come from the asteroids which are crushed by impacts with other asteroids. In some cases, they originate from the moon and possibly from Mars and comets (What are Meteorites?, n.d).
As indicated in the graph below, the meteorites that are about 1mm in diameter hit the Earth approximately once in every thirty seconds. But on the other hand, those that are larger in size hit the Earth less often. For instance, as indicated in the graph, the objects that are 1 km in diameter hit the planet once in every 1 million years and those that have a diameter of ten kilometers strike the Earth once in every one hundred million years (Nelson, 2011).
The Consequences of the Earth Being Hit
An asteroid which may come down from the sky would have a large quantity of energy. For instance, in the year 2008, it was expected that the asteroid named 1997XF11 would fall very close to the Earth but would miss it. If something was done in order that it actually hit the earth, what would result was an asteroid that is one mile wide striking the surface of the earth at a speed of thirty thousand miles per hour.
An asteroid that is moving at such a great speed would possess the energy that is approximately equivalent to one million megaton bomb. There is a high likelihood that an asteroid of this size would clear most of the life on this planet (Brain, 2012).
In case an asteroid is the same size as a twenty-story building, it possesses an amount of energy that is the same as the biggest nuclear bomb made in the current day. An asteroid of this size would make structures which are strengthened using concrete to become flat “five miles from ground zero” (Brain, 2012). It would entirely cause destruction to the big cities (Brain, 2012).
Moreover, a one-mile wide asteroid possesses the energy which is one million times higher than the Hiroshima bomb. It has the capacity to crash everything for between one hundred and two hundred miles out from the ground zero. In case an asteroid dropped in the sea, it would bring about great tidal waves, several hundreds high and this “would entirely scrub all the coastlines in the surrounding area” (Brain, 2012).
Moreover, if a large meteorite fell in the ocean, there would be generation of a gia ant tsunami. The Tsunami would facilitate production of wavethe s that could easily flood the continents. There could also be production of muchthe steam resulting from the abrupt evaporation of the water in the ocean.
The carbon dioxide produced as well as water vapor would stay in the atmosphere for a longer time after settling of dust. Both the steam and CO2 are gases which bring about a warming effect. Therefore, at the time the first global cooling has occurred, there will be global warming in the atmosphere for a long period of time thereafter.
Another effect following the falling of large meteorites would be production of hthe uge amounts of dust in the atmosphere. This would lead to blocking of the radiation from the sun from entering into the atmosphere. It would be after several months before the dust settles.
In the meantime, there would be total continuous darkness on Earth and there would be dropping of the temperatures across the entire Earth. The blocking of the solar radiation would as well lead to a reduction in the capacity of the organisms to undertake the process of photosynthesis. Photosynthesis by the living organisms forms a base of the food chain and the effect that would be there would be disruption of the entire ecosystems, possibly resulting in all the living organisms dying (Nelson, 2011).
Chances of the Earth Being Hit and Dealing with the Threat
There exists much evidence that the earth has already been hit by asteroids several times all through history. There are large numbers of asteroids or meteors in the orbit around the sun. A large number of these objects are referred to as “near-Earth steroids” and this i,s for the reason that they possess energy which, over and over again, bring them nearer to and intersect with the orbit of the earth (Scientific American, 2004).
“Even if there is a low likelihood that any one particular asteroid will hit the earth, there is still likelihood that the earth will be hit at some day by an asteroid”. Basing on the present impacts rate, it could be expected that a single large asteroid would hit this planet “every one hundred million years” (Scientific American, 2004).
Because of this, a number of programs like the “Lincoln Near-Earth Asteroid Research” project set up at the Massachusetts Institute of Technology have been carried out across the globe to find out and to monitor possible asteroids that are threatening the planet (Scientific American, 2004).
At the time the discovery of a new asteroid is done, an analysis is carried out by the experts in order to determine whether or not its orbit around the sun could make it to come close to this planet. The astronomers take the photographs of the asteroid shortly after it being discovered so that they can carry out the prediction of its possible orbital route for the near future.
A comparison of the orbit that is predicted as well as the Earth position is carried out in order to find out any times when they can get close to one another (Scientific American, 2004).
Even if the astronomers can engage in the computation of a highly likely orbit of such observations, every one observation made of the position of the asteroid carries some lack of certainty (Scientific American, 2004). A larger number of the asteroids are small in size and even the power of a big telescope can not facilitate determination of their positions accurately. Lack of certainty in regard to the position of the asteroid results in the lack of certainty in how best the determination of the rate at which it moves and its direction can be carried out. Consequently, many likely asteroid orbits can be foreseen within these uncertainty windows (Scientific American, 2004).
Keen simulations are employed in the computation of the upcoming orbital path with the original positions as well as speeds that are chosen at random within the error scope of the telescope. There is generating of many of the computer simulations for every single asteroid. The likelihood that any single one will really hit the planet is given by the “extrapolated paths fraction that results into an impact” (Scientific American, 2004, p1).
For instance, in case there is calculation of one million different likely orbits, and one of them results into an impact, one may conclude that the “odds of the asteroid hitting the earth are one million to one” (Scientific American, 2004). However, there is need for the experts in this field to carry out more research and to ensure there is early detection in order for the appropriate technology to be used to deflect the asteroids or meteors to prevent them form hitting the Earth.
Conclusion
Over time, the Earth has been hit by various heavenly bodies that have been smaller in size. It has been found out that those meteors which are 1mm in diameter hit the Earth once very thirty seconds. On the other hand, the large objects that are one kilometer wide may hit the Earth once every one million years. This implies that the larger the size of the object he longer it takes to hit the Earth.
However, if the Earth were to be hit by a large meteor or asteroid, there would be immense consequences that may even contribute to the destruction of the entire life on Earth. Even if the chances of the Earth being hit are very minimal, there is need for the experts, especially the astronomers, to engage in clearly studying the asteroids and meteors and their chances of hitting the Earth in order for the appropriate measures to be taken, such as deflecting these heavenly bodies to prevent them from hitting the Earth.
References
Brain, M. (2012). What if an asteroid hit the earth?
Kindersley, D. (2007). Asteroids.
Nelson, S. A. (2011). Meteorites, impacts and mass extinction.
Scientific American, (2004). What is the chance of an asteroid hitting earth and how do astronomers calculate it?
What are Meteorites? Web.
What are meteors, (2011).