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A brilliant object crossed the skies of several Russian cities on June 21 and produced an explosion equivalent to 2.8 kilotons.
It was a meteor of about 4 meters that no one detected. This did not cause any damage. The following days, near Yelets, scientists from the Ural Federal University found pieces of rock about three centimeters, reports the EarthSky specialist site
A few weeks earlier, the June 2, another rock came from the space. of just two meters, which was detected a few hours earlier by the Catalina program supported by NASA, has disintegrated into the atmosphere. He received the name 2018 LA.
There was not much time to predict its trajectory in detail, but in Botswana, Africa, a bolide (bright meteor) was reported that coincided with the object. He entered the atmosphere at a speed of 17 kilometers per second and disintegrated several kilometers above the surface.
Occasional Incidents or Frequent Cases? The Earth is exposed to this clbad of visitors: asteroids. However, what is the danger?
Today, for the fourth year, is celebrated the day of the asteroid recognized by the United Nations, who remembers the disaster of Tunguska, Siberia, exactly 110 years ago, devastating with its explosion area of about 2000 square kilometers, five times the size of Medellín or 1.2 that of Bogotá.
A day to remember that you have to look at the sky, not from time to time but every second and in this task there are several programs like that
About Tunguska exploded a rock about 40 to 60 meters which produced an equivalent detonation between 5 and 10 megatons. The area burned, sparsely populated, although only in the late 1920s, more than 15 after the event, an expedition documented what happened.
The periods in which the sky was not followed.
"This is only the third time that an asteroid on an impact trajectory has been discovered," said Lindley Johnson of NASA's Defense Office.
Paul Chodas, director of NASA's Center for Near-Object Studies. "It was also only the second time that a high probability of impact was predicted before that happened," he added.
The Official Report
To date, the National Council of Science and Technology The United States has delivered the action plan and readiness strategy on close objects, in which it takes stock of the asteroids traced up to today.
It is that even the smallest ones have a high destructive power. In 2013, on February 15, a rock of about twenty meters exploded on Chelyabinski, Russia, with 20 to 30 times more energy than those of the first atomic bombs. He touched dozens of buildings in several cities.
It is estimated that there are about 10 million objects near more than 20 meters, very difficult to detect before the shot.
NASA considers that there are more than 300,000 meters over 40 meters, which would generate a local impact and whose detection would only be achieved a few days before the impact.
The detection programs seek to find those over 140 meters, which would cause regional or even continental damage. It is estimated that there could be about 25,000, of which only one-third was identified
. These would reach a minimum energy of 60 megatonnes of TNT, more than any other nuclear device tested so far. Fortunately, they are easier to follow.
Asteroids longer than one kilometer would cause global damage. The one that triggered the extinction of dinosaurs 65 million years ago was about 10 kilometers away. They are rarer and NASA believes it has identified the largest.
Today the most concerned is 99942 Apophis, discovered in 2004, which will pbad in 2029 and it is still difficult to exclude an impact because some parameters are unknown, according to the 2013 report. 325 meters
The other uncertainty comes from unknown comets that continually come from the confines of the Solar System and whose trajectory is known only as soon as they appear.
Therefore, the two rocks that fall this month remind us you must continue to look at the sky.
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