A Football Field Sized Asteroid Just Missed Hitting the Earth

The BBC Internet edition reported on the 20th that it was clarified lately that a football-field size asteroid approached to 120,000 kilometers away from the Earth. We almost experienced an explode more powerful than a hydrogen bomb although it may not be disastrous as in the movies like Armageddon or Deep Impact.

The astronomers of Lincoln Near Earth Asteroid Research (Linear) in New Mexico, America reported that they found out on the 17th that an asteroid named ‘2002MN’, which had a diameter of 50 ~ 120m, was approached to 120,000km away from the Earth with a speed of 10km per second and passed her. It is the 6th time ever that an asteroid entered between Moon and the Earth (380,000km away from the Earth), and it is the first time that an asteroid approached to the Earth this close since December, 1994.

The experts analyzed that it will not damage the whole planet when this size asteroid hit the Earth; however, it might damage her as much when an asteroid hit the Earth at Tunguska, Siberia in 1908. Dr. Benny Pager of John Moors University, Liverpool says, “there is a good chance that we may experience collision as big as Tunguska in our life time,”

At that time, an asteroid with a diameter of 60m hit Siberia and 2000 square kilometers of forests were burnt to the ground.

Scientists estimate that the explosive power of that was as much as 10 ~ 20 mega tons, which is 1000 times more powerful than the nuclear bomb that was dropped in Hiroshima, Japan (0.01 mega ton). The probability of this size asteroid collide with the Earth is once in 1000 years.

If an asteroid with a diameter of 7km or more collides with the Earth, the damage may affect the whole planet as seen in the movies, and the probability of that is once in 10 million years. If the diameter is 1.7km or more, it can make a huge tsunami, and the probability of that is once in 20,000 years.

Scientists worry about the fact that the coming of the asteroid was reported 3 days after the actual occurrence. To find out about it as soon as possible is the key to prepare for it. Doctor John Davis of Royal Observatory of Edinburgh explained that it was impossible to find the asteroid with a normal telescope because it was aligned with Sun at that time.

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