Understanding What Exploded Over Russia
Two weeks after an asteroid exploded over Russia's Ural mountains, NASA scientists are making progress understanding the origin and make-up of the unexpected space rock. In a one in a million coincidence that still has experts shaking their heads, the small asteroid completely unrelated to 2012 DA14 struck Earth only hours before the publicized event. The most telling information comes from a network of infrasound sensors operated by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The asteroid was about 17 meters in diameter, weighed about 10,000 metric tons, and struck Earth going about 40,000 mph.
Transcript
00:00:02 [Music] what exploded over Russia presented by science at Nasa when the sun rose over Russia's Euro mountains on Friday February 15th many residents of nearby chubin already knew that a space Rock was coming later that day an asteroid named 2012 da14 would pass by Earth only 17,200 mil above
00:00:26 Indonesia there was no danger of a collision NASA assured the public maybe that's why when the morning Sky lit up with a second sun and a shock wave shattered windows in hundreds of buildings around chubin only a few people picking themselves off the ground figured it out right away this was not a crashing plane or a rocket attack it was a meteor
00:00:51 strike the most powerful since the tunguska event of 198 says Bill Cook of NASA's meteoroid environment office in a one in a million coincidence that still has NASA experts shaking their heads a small asteroid completely unrelated to 2012 da14 struck Earth only hours before the publicized event these are rare events and it is incredible to see them happening on the same day says Paul
00:01:14 choas of NASA's near Earth object program at JPL researchers have since pieced together what happened the most telling information came from a network of infrasound sensors operated by the comprehensive Test Ban Treaty Organization their purpose is to monitor nuclear explo explosions infrasound is a type of very
00:01:33 lowf frequency sound wave that only elephants homing pigeons and a few other animals can hear it turns out that meteors entering Earth's atmosphere cause ripples of infrasound to spread through the air of our planet by analyzing infrasound records it is possible to learn how long a meteor was in the air which direction it traveled and how much energy it
00:01:53 unleashed the Russian meteor's infrasound signal was detected by multiple stations including one in Alaska more than 6,500 km from chubin Western Ontario professor of physics Peter Brown analyzed the data the asteroid was about 17 m in diameter and weighed approximately 10,000 metric tons he reports it struck Earth's atmosphere at 40,000 mph and
00:02:16 broke apart about 12 to 15 mil above Earth's surface the energy of the resulting explosion exceeded 470 kilotons of TNT for comparison the first atomic bombs produced only 15 to 20 kilotons based on the trajectory of the fireball analysts have also plotted its orbit it originally came from the asteroid belt about 2.5 times farther from the Sun
00:02:39 than Earth says cook comparing the orbit of the Russian meteor to that of 2012 da14 NASA orbit analysts have shown that there is no connection between the two these are independent objects cook says the fact that they reached Earth on the same day one just a little closer than the other appears to be a complete coincidence infrasound records confirm that the meteor entered the atmosph
00:03:00 mosphere at a shallow angle of about 20° and lasted more than 30 seconds before it exploded the loud report which was heard and felt for hundreds of miles marked the beginning of a scientific scavenger hunt thousands of fragments of the meteor are now scattered across the eural countryside and a small fraction have already been found preliminary reports mainly communicated through the
00:03:22 media suggest that the asteroid was made mostly of stone with a bit of iron in other words a typical asteroid from Beyond the orbit of Mars says cook there are millions more just like it and that is something to think about as the cleanup in chubin continues for more news about things coming out of the blue visit science.nasa.gov