Avi Blizovsky
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An asteroid the size of three football fields will make the closest approach to Earth by an object of its type in history.
It will cross between the Earth and the Moon and come even closer than the communication satellites, although astronomers say there is an extremely small chance of it colliding with the Earth. "Concerned earthlings need not fear so much for the next 24 years, however, as asteroid 2004 MN4 is due to approach Earth no earlier than 13pm London time, 2029 April XNUMX (midnight our time).
From the latest calculations of the rock's orbit it seems that it will be visible to the naked eye above Europe. It will shine in the sky as a fast but dim star - the first asteroid in modern history that will be clearly visible from Earth without the aid of a telescope or binoculars.
The asteroid was first discovered in June 2004 and calculations of its trajectory made by astronomers at the end of the year suggest that there is a 1 in 60 chance that it will collide with the Earth. However, within a week they changed the calculation and showed that the chance tends to zero.
If it crashes, it will be a collision with the force of 20 hydrogen bombs at once, and it will turn vast areas of land into a desert or cause a huge tsunami wave if it falls in the sea.
The latest examination of the calculations made it possible to refine the trajectory and predict that the asteroid will come within striking distance of the Earth - 36 thousand kilometers - within the orbit of the geostationary communication satellites and about a tenth of the distance to the Moon. This is without a doubt the asteroid that will come the closest over most of the ten closest so far. Only two asteroids came closer but they were much smaller objects - tens of meters and not 350 meters like the asteroid 2004 MN4.
Prof. Mark Bailey Bailey, Director of the Armagh Observatory, said that the danger posed by the asteroid is quite small even though it will come very close. "I think everyone says he will miss. It will pass quite close so that we can see it with a small telescope or even with the naked eye" said Prof. Bailey. "It's like standing at a train station and watching an express train pass a meter away from you. You're close, but there's no danger in that." said.
Large asteroids have crashed into Earth in the past and the largest ones have caused mass extinctions of species on a global scale. They could create something akin to a nuclear winter by blasting huge plumes of dirt and debris into the atmosphere and blocking sunlight for several years.
Last fall, a larger asteroid, Totatis, about 5 kilometers long and 2.3 kilometers wide, made its closest approach to Earth but the distance was still 4 times the distance of the Moon from Earth or 40 times the expected distance of the new asteroid. It was also not visible to the naked eye.
Steve Chelsea, of NASA's Jet Propulsion Laboratory in Pasadena, California, said asteroid 2004 MN4 is unusual because we know a lot about its orbit before it approaches in 24 years. All the other 10 asteroids that came close surprised us.” The scientists estimate that an object of this size approaches the Earth about once every 1,300 years. Asteroid 2004 MN4 orbits the Sun, but unlike most of the asteroids orbiting the Sun between the orbits of Mars and Jupiter, this asteroid is close to Earth's orbit and there is a high probability of its further approaches in the future. "However, our current risk analysis for 2004 MN4 shows that no further approaches to Earth are expected during the 21st century." said Dr. Chelsea.
For information in the Independent
They knew cosmic collisions
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