Monday, February 18, 2013

Meteorite Slams into Russia-Didn't See That Coming

The GIF animation below comes from NOAA and consists of 8 separate images captured by satellites in 15 minute increments until the vapor trail blends into the reflected light of the morning sun.

NOAA Environmental Visualization Laboratory - Meteorite Slams into Atmosphere Above Chelyabinsk, Russia

From NOAA Environmental Visualization Laboratory  Meterorite Slams into Atmosphere above Russia
On February 15, 2013 at around 9:20 am local time a meteor entered the atmosphere above Chelyabinsk, Russia. According to the revised information from the NASA Jet Propulsion Laboratory, in Pasadena, California, the meteor was 55 feet in diameter and had an estimated mass of 10,000 tons. The meteor was traveling at about 40,000 miles per hour when it entered the atmosphere, streaking across the sky for 32.5 seconds, releasing a sonic boom that blew out windows and doors and exploded in the atmosphere above the earth. The meteor was a made of rock material that grazed the atmosphere and exploded into what scientists expect to be a large number of meteorites. Scientists now believe that 500 kilotons of energy was released in the explosion. This is more than 33 times the size of the explosion at Hiroshima during World War II. Peter Brown, a scientist at the University of Western Ontario, Canada used infrasound data collected from monitoring stations around the world to estimate this information. Infrasound data is monitored around the world to monitor for nuclear testing to ensure compliance with nuclear treaties.

Scientists had been monitoring the sky for the 2012 DA14 asteroid that had been discovered in 2012 and was scheduled to make a close pass by earth on the same day, but did not see the Russian meteor coming because it was coming from the east- the daylight side. The trajectory of the Russia meteor was significantly different than the trajectory of the asteroid 2012 DA14, which hours later made its flyby of Earth, making it an unrelated coincidence. The 2012 DA14 meteor was a 130,000 ton 150 foot diameter meteor that passed 17,200 miles above earth without event.

The Russia meteor is the largest reported meteor strike since 1908, when a meteor hit Tunguska, Siberia, but meteors strike earth all the time. Most are small and burn up in the upper atmosphere, some are seen in the night sky as shooting stars.  These days satellites monitoring the earth for missile launches and the infrasound monitoring stations can quickly identify a large meteor strike, but in earlier times large meteors could have struck the earth in uninhabited areas or the ocean and been unnoticed. Small meteor fragments do occasionally strike earth (becoming meteorites by hitting earth) and injure a couple of people, but nothing on the magnitude of this meteor where over 1,000 people were reported to be injured from broken glass and the damage of doors and windows blown out by the sonic boom. NASA states that though meteorites strike earth daily, a meteor of this size is a once in a century event with even larger hits occurring every couple or more millennium.  

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