Today, February 15, 2013 will be remembered, as a large meteor hit Russia and the near earth object (NEO) asteroid will pass 'very close' by earth, estimates the asteroid will pass as close as 27,700 km (17,200 mi) from the earth's surface, and closer to earth than our ring of orbiting geo-synchronous satellites (See NASA JPL Orbit Diagram).
DA14 will pass nearby, and scientists anticipate a near earth fly-by with no impact. DA14 earth impact risk-based velocity is calculated at 12.72 km/s, and an estimated 3.5e+00 MT, or 3.5 megatons. The previous data was extracted from NASAs jpl website. Additionally, DA14 will pass by close enough that our earth's gravitational field will increase drag and alter this asteroid's orbit, and foreseeably ejecting this particular vNEO into a safer trajectory for future orbits around the sun.
In reality, the DA14 asteroid is actually a very small one with an approximate estimated diameter of 50 meters or 160 ft. Compared with the hoards of NEOs that will pass by earth at more distant trajectories this year (http://neo.jpl.nasa.gov/ca/). However, the DA14 asteroid is many times larger than the fly-by meteorite that just exploded over Russia causing so much widespread damage today. For this reason, and resulting destruction from such a relatively small object, scientists are reevaluating asteroid trajectory an impact risk factors. There may be development of a sub-category emerging of not so detectable very near earth objects (vNEOs) of lesser scales.
In December, on the 13th of 2012, I wrote an article about a NEO that was discovered only 3 days before by an astronomer, and that NEO harmlessly passed by earth. In this regard, we cannot have too many 'trained' space weather viewers, astronomers, NEO reporters and trackers. Such global space weather observers are similar to the terrestrial-based Skywarn weather program. Skywarn trains people to accurately identify and report dangerous local severe storms in time to hopefully notify towns and cities of impending natural disasters such as tornadoes etc., before they arrive. I anticipate expansion of a global space weather Skywarn program in the future.
However, this morning in Russia, a large meteorite did explode and hit causing a remarkable amount of widespread damage and hundreds of injuries over a large area. This Russian meteorite was on a different trajectory than 2012 DA14, but may have been on a somewhat similar orbit path as a tag-along with DA14, or may have had a gravitationally disturbed trajectory, but such evaluations are yet to be determined.
Who knows, we as earthlings may see governments launching additional early-warning satellite systems into orbit with the advanced means to identify a sub-category vNEOs. Early warning systems, including technology with both terrestrial and cosmic origins, and such a grid of early warning sensors seem essential for humanity to plan, manage, and provide links for survival for all species of terrestrially originated life into the future, as space exploration extends our reach into our solar system, and maybe someday, beyond.
Below are several early links to the large meteor that hit near Chelyabinsk, Russia today:
Meteor Hits Russia Big Explosion Chelyabinsk 15-2-2013
INCREDIBLE - Russian Meteor Shower- Russia meteorite may be part of Giant - RT News
Meteorite Shower Hits Russia Injuring 500 (BREAKING NEWS) - 15th Feb 2013
Report: Meteor hits Russia - Feb 14, 2013