3D simulation of the Chelyabinsk meteor explosion by Mark Boslough, rendered by Brad Carvey using the CTH code on Sandia National Laboratories' Red Sky supercomputer. Andrea Carvey composited the wireframe tail. Photo by Olga Kruglova.

That Feb. 15 asteroid that burst over the Russian city of Chelyabinsk has reset thinking regarding damage caused by smaller space rocks. Also, there may be more small asteroids than formerly thought.

These findings and other research observations are on view tonight on a special PBS television airing.

The Russian asteroid fireball earlier this year injured about 1,500 people and damaged more than 7,000 buildings, collapsing roofs and breaking thousands of windows.

Sandia physicist Mark Boslough was part of a team of 33 researchers who completed detailed study of the 500-kiloton airburst over Chelyabinsk, examining the characteristics of the fireball. At its peak, the airburst appeared to be 30 times brighter than the sun.

Using data collected by visiting the area shortly after the asteroid struck, along with data from an international team, Boslough developed several additional simulations that he and other researchers have used to model the explosion and estimate the force of the blast.

Risk from airbursts

“Because the frequency of a strike of an asteroid of this size has exceeded expectations, with three such strikes in just over a century (Chelyabinsk, Tunguska in 1908 and a large airburst in the South Atlantic in 1963 detected by infrasound), the number of similar-sized asteroids capable of causing damage may be greater than suspected,” Boslough said in a Sandia press statement.

“We really have to rethink the risk from airbursts. Chelyabinsk was unusual due to the a low inclination at which it entered the atmosphere, but 90 percent of objects enter the atmosphere at a steeper angle and cause more damage on the surface,” Boslough said.

Will future asteroids trigger massive extinctions? How about mining asteroids for precious minerals?

Join Sandia’s Boslough and others that will explore these issues during a PBS airing tonight, first airing on November 20 at 9 pm on PBS.

For more information on the show, go to:

http://www.pbs.org/wgbh/nova/earth/asteroid-doomsday.html

By Leonard David