Meteor Caused Damage In Russia, Asteroid Passed Within 17,000 Miles Of Earth Friday

Two objects with the potential to cause substantial damage on Earth left the planet relatively unscathed in close encounters on Friday. In one, a meteor exploded spectacularly over the Russian city of Chelyabinsk, raining down fragments of space rock which, along with shattering glass, reportedly injured several hundred people. The shock wave from the meteor blew out thousands of windows in the city.

NASA said the estimated size of the object, prior to entering Earth's atmosphere, has been revised upward from 49 feet to 55 feet, and its estimated mass has increased from 7,000 to 10,000 tons. Also, the estimate for energy released during the event has increased by 30 kilotons to nearly 500 kilotons of energy released. These new estimates were generated using new data that had been collected by five additional infrasound stations located around the world – the first recording of the event being in Alaska, over 6,500 kilometers away from Chelyabinsk. The infrasound data indicates that the event, from atmospheric entry to the meteor's airborne disintegration took 32.5 seconds. The calculations using the infrasound data were performed by Peter Brown at the University of Western Ontario, Canada.

"We would expect an event of this magnitude to occur once every 100 years on average," said Paul Chodas of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, CA. "When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."

The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia.

While unrelated, it is noteworthy that the meteor event in Russia occurred on the same day that asteroid 2012DA14 made a near pass to Earth, coming as close as about 17,000 miles to the planet. DA14 is estimated to have been about three times the size of the meteor.

In a statement released to the media, The B612 Foundation ... which is developing a private space telescope to detect near-Earth objects that might threaten out planet ... says it believes "we should find threatening asteroids before they find us. The undetected meteor explosion over Chelyabinsk on February 15 is our wake-up call that the Earth orbits the Sun in a shooting gallery of asteroids, and that these asteroids sometimes hit the Earth. On this same day, a separate and larger asteroid, 2012 DA14, narrowly missed the Earth passing beneath the orbits of our communications satellites.
 
"We have the technology to deflect asteroids, but we cannot do anything about the objects we don't know exist. To date, less than 1% of asteroids larger than the one that leveled Tunguska in 1908 have been tracked. The B612 Foundation Sentinel Space Telescope, to be launched in 2018, will provide a comprehensive map of the locations and trajectories of threatening asteroids and will give humanity the decades of warning needed to prevent asteroid impacts with existing technology.
 
"By the end of its planned lifetime, Sentinel will have discovered well over 90% of the asteroids that could destroy entire regions of Earth on impact (those larger than 350ft in diameter) and more than 50% of the currently unknown DA14-like near-Earth asteroids.
 
"The B612 Foundation has undertaken this Sentinel project as a non-governmental initiative, somewhat akin to a growing number of private space ventures originated in the past few years. The foundation is not undertaking this project for profit; we are a non-profit corporation. Our motivation is strictly to ensure the survival of life on Earth – all of it. And while NASA is cooperating with us by providing certain communication and analytic services, we are excited, as a private venture, to welcome the participation of all the crew of Spaceship Earth in this great endeavor.
 
"We have to answer the question: Does the crew of Spaceship Earth raise our awareness and accept responsibility for our voyage into the future? Or do we sit back as passengers, comfortably assuming that there must be a captain and crew doing this job on our behalf? The B612 Sentinel mission is testament to our belief that we, together, are responsible for the future of life on our small planet."

(Meteor impact area map provided by NASA, Sentinel image courtesy B612 Foundation)

FMI: www.nasa.gov, www.b612foundation.org