Astrophys. J. 835, 157 (2017)

The Chelyabinsk meteorite became a media celebrity after the videos of its explosion in mid-air, occurring in February 2013 near the homonymous city, went viral on social networks. This extensive media coverage contributed to raising awareness of the risks linked to near-Earth asteroids even of relatively small dimensions (Chelyabinsk had a radius of ∼20 m; small compared with the 10-km-sized object that caused the extinction of the dinosaurs). It is thus fitting that the Chelyabinsk meteorite could help to protect us from such events.

Credit: AAS/IOP

One of the ways to deflect an incoming meteorite is to hit it with a small projectile to change its orbit. However, the final result depends strongly on its physical characteristics. Carles Moyano-Cambero and colleagues determine the mechanical properties of pieces of Chelyabinsk, characterized by different lithology, by performing non-intrusive microscopic indentation on them in the laboratory (pictured) at the Institute of Space Sciences in Barcelona (CSIC-IEEC) and comparing the response with control samples of different composition and internal structure.

Moyano-Cambero et al. find that an impacting deflector would be more efficient if it hit a near-Earth object in an area of light-coloured materials, which could be distinguished from other regions by means of a close-up spectroscopic survey. In addition, shock-melt veins are a structural weakness particularly responsive to impact projectiles.