Russian meteor unrelated to near earth asteroid, NASA preliminary data, 55 feet 10K tons, Trajectory significantly different, Asteroid groups in similar orbits
“Unrelated: 1 not connected to a subject that you are thinking about or discussing 2 not part of the same family”…MacMillan Dictionary
Freedom is the freedom to say that two plus two make four. If that is granted, all else follows.”…George Orwell, “1984”
According to NASA:
“Preliminary information is that this object was unrelated to asteroid 2012 DA14”
I would caution the use of the word “unrelated” in reference to the meteor.
From NASA February 15, 2013.
“Russia Meteor Not Linked to Asteroid Flyby”
“Update: February 15, 2013 7pm PST
New information provided by a worldwide network of sensors has allowed scientists to refine their estimates for the size of the object that entered that atmosphere and disintegrated in the skies over Chelyabinsk, Russia, at 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15).
The estimated size of the object, prior to entering Earth’s atmosphere, has been revised upward from 49 feet (15 meters) to 55 feet (17 meters), 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, Calif. “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 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 a completely unrelated object. The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia.
Preliminary information indicates that a meteor in Chelyabinsk, Russia, is not related to asteroid 2012 DA14, which is flying by Earth safely today.
The Russia meteor is the largest reported since 1908, when a meteor hit Tunguska, Siberia. The meteor entered the atmosphere at about 40,000 mph (18 kilometers per second). The impact time was 7:20:26 p.m. PST, or 10:20:26 p.m. EST on Feb. 14 (3:20:26 UTC on Feb. 15), and the energy released by the impact was in the hundreds of kilotons.
Based on the duration of the event, it was a very shallow entry. It was larger than the meteor over Indonesia on Oct. 8, 2009. Measurements are still coming in, and a more precise measure of the energy may be available later. The size of the object before hitting the atmosphere was about 49 feet (15 meters) and had a mass of about 7,000 tons.
The meteor, which was about one-third the diameter of asteroid 2012 DA14, was brighter than the sun. Its trail was visible for about 30 seconds, so it was a grazing impact through the atmosphere.
It is important to note that this estimate is preliminary, and may be revised as more data is obtained.”
We know that asteroids can travel in “family” groups in the asteroid belt. This is believed to be the result of collisions that break up asteroids with the pieces continuing to travel in similar orbits.
“Several asteroids, including (243) Ida, (45) Eugenia, and (762) Pulcova, are known to have small moons of their own.”
“Collisions gave rise to the Hirayama families and at least some of the planet-crossing asteroids. Tiny fragments from the latter enter Earth’s atmosphere to become sporadic meteors, while larger pieces survive passage through the atmosphere to end up as meteorites. The very largest produce craters such as the Barringer Crater, and one may have been responsible for the extinction of the dinosaurs.”
“An asteroid group is a collection of asteroids that move in generally similar orbits. Within a group there may be one or more families of asteroids whose orbital characteristics are so much alike that they almost certainly came from the breakup of a single parent body.”
Whether or not this meteor was officially associated with the near earth asteroid, it is certainly plausible and could happen in the future.
If NASA had a clear understanding of the meteor and its trajectory, why wasn’t Russia warned?