November 5, 2013 is a big day for the Meteor Physics group of astronomers, staff, students as they have teamed with international researchers to publish two significant papers in the electronic version of Nature, The International Weekly Journal of Science. This will follow in print form on November 14.
The Chelyabinsk event of 15 Feb. 2013, having an energy equivalent to 500 kilotons of TNT, was the largest well-documented meteor event since the Tunguska event of 1908.
Analysis of the Chelyabinsk object's in-atmosphere trajectory from video records has found that its orbit was similar to the orbit of the 2-km-diameter Near-Earth Asteroid 86039 (1999 NC43).
There is a possibility that the Chelyabinsk object was created through a collision between asteroid 86039 and another asteroid.
It is also very interesting that the Cheyabinsk Asteroid approached from the Sun's direction, making it essentially undetectable in telescopes.
A detailed summary of the first paper is given on Paul Wiegert's web site.
This paper in now online in Nature.
The second paper shows that objects of the size of Chelyabinsk, in the 15-50m range, have not only been overestimated in their damage estimates, and hence mis-reported from direct observation of damage, but they may also be ten times more numerous than previously estimated. Combined, these two findings imply that impacting objects of this size present a much larger cumulative damage threat than previously recognized.
The second paper is also now online in Nature.
Western authors in these papers include: Prof. Peter Brown, Prof. Margaret Campbell-Brown, Prof. Paul Wiegert, David L. Clark, Elizabeth Silber, Rob Weryk, Jason Gill, and Zbyskek Krzeminski, as well as Western graduates Wayne Eduards and Rhiannon Blaauw, and David Uren.