The Chelyabinsk superbolide: a fragment of asteroid 2011 EO40?

TL;DR

This study investigates the origin of the Chelyabinsk superbolide by analyzing its orbit, identifying a potential asteroid family, and suggesting 2011 EO40 as its most probable parent body, indicating a recent cluster formation within 20-40 kyr.

Contribution

The paper presents a multistep approach combining orbital analysis, asteroid family identification, and N-body simulations to link the Chelyabinsk impactor to asteroid 2011 EO40.

Findings

Identified a Chelyabinsk asteroid family with multiple small members.

Most probable parent body of the impactor is asteroid 2011 EO40.

Cluster age estimated to be 20-40 thousand years.

Abstract

Bright fireballs or bolides are caused by meteoroids entering the Earth's atmosphere at high speed. On 2013 February 15, a superbolide was observed in the skies near Chelyabinsk, Russia. Such a meteor could be the result of the decay of an asteroid and here we explore this possibility applying a multistep approach. First, we use available data and Monte Carlo optimization (validated using 2008 TC3 as template) to obtain a robust solution for the pre-impact orbit of the Chelyabinsk impactor (semimajor axis = 1.62 au, eccentricity = 0.53, inclination = 3.82 deg, longitude of the ascending node = 326.41 deg and argument of perihelion = 109.44 deg). Then, we use this most probable orbit and numerical analysis to single out candidates for membership in, what we call, the Chelyabinsk asteroid family. Finally, we perform N-body simulations to either confirm or reject any dynamical connection between candidates and impactor. We find reliable statistical evidence on the existence of the Chelyabinsk cluster. It appears to include multiple small asteroids and two relatively large members: 2007 BD7 and 2011 EO40. The most probable parent body for the Chelyabinsk superbolide is 2011 EO40. The orbits of these objects are quite perturbed as they experience close encounters not only with the Earth-Moon system but also with Venus, Mars and Ceres. Under such conditions, the cluster cannot be older than about 20-40 kyr.