Jadeite in Chelyabinsk meteorite and the nature of an impact event on its parent body.

ABSTRACT: The Chelyabinsk asteroid impact is the second largest asteroid airburst in our recorded history. To prepare for a potential threat from asteroid impacts, it is important to understand the nature and formational history of Near-Earth Objects (NEOs) like Chelyabinsk asteroid. In orbital evolution of an asteroid, collision with other asteroids is a key process. Here, we show the existence of a high-pressure mineral jadeite in shock-melt veins of Chelyabinsk meteorite. Based on the mineral assemblage and calculated solidification time of the shock-melt veins, the equilibrium shock pressure and its duration were estimated to be at least 3-12?GPa and longer than 70?ms, respectively. This suggests that an impactor larger than 0.15-0.19?km in diameter collided with the Chelyabinsk parent body at a speed of at least 0.4-1.5?km/s. This impact might have separated the Chelyabinsk asteroid from its parent body and delivered it to the Earth.

SUBMITTER: Ozawa S 

PROVIDER: S-EPMC4030444 | biostudies-literature | 2014 May

REPOSITORIES: biostudies-literature