National Optical Astronomy Observatory | 2017 Aug 30
In 2013 a small meteoroid, the size of a house, hurtled through Earth’s atmosphere and exploded over the Russian city of Chelyabinsk. The explosion shattered windows, and more than a thousand people were treated for injuries from flying debris. How many similar-sized rocks have orbits that bring them close to Earth? A new study has answered that question using the Dark Energy Camera (DECam) on the Blanco telescope at the Cerro Tololo Inter-American Observatory. The result lends new insights into the nature and origin of small meteoroids.
Near Earth Objects (NEOs) are asteroids or comets whose orbits bring them close to Earth’s orbit. Their close approach makes them a potential Earth-impact hazard capable of causing widespread destruction.
While very large (10 kilometer-sized) impactors can induce mass extinction events like the event that led to the demise of the dinosaurs, much smaller impactors can also wreak havoc. The meteoroid that exploded in Chelyabinsk unleashed a powerful shock wave that destroyed buildings and blew people off their feet. Relatively petite at a ‘mere’ 17 meters in diameter, comparable to the size of a 6-story building, the impactor, when it exploded, released about ten times the energy of the Hiroshima atomic bomb. ...
The size distribution of Near Earth Objects larger than 10 meters - D. E. Trilling et al
- arXiv.org > astro-ph > arXiv:1707.04066 > 13 Jul 2017