The Chelyabinsk meteor was seen as a fireball, caught here on a car's dashboard camera. Image Credit: RIA NOVOSTI/Science Photo Library
The meteor that exploded in the sky over Chelyabinsk, Russia in February may not have been alone, new research suggests.
According to Carlos and Raúl de la Fuente Marcos, two brothers researching meteor and asteroid orbits at the Complutense University of Madrid, the meteor may have been just one member of an asteroid 'family' on similar orbits - with remaining family members still posing a threat to Earth.
The brothers came to this conclusion after comparing ten 'best estimates' of the Chelyabinsk meteor's orbit with the orbits of all asteroids catalogued by NASA.
As an article to be published in Monthly Notices of the Royal Astronomical Society: Letters reveals, their search turned up around 20 potential siblings, including the large asteroid 2011 EO40, which is already listed by NASA as 'potentially hazardous'.
The de la Fuente Marcos brothers suggest the Chelyabinsk meteor, 2011 EO40 and the other asteroids identified may all be fragments of a previous, larger body that broke up between 20,000 and 40,000 years ago.
However, these results are by no means certain.
Other asteroid watchers have pointed out that the 'best estimates' of the Chelyabinsk meteor's orbit are just that, given that the 18m-wide object was only observed for a very short time between emerging out of the Sun's glare and turning into a huge fireball over Russia.
The orbits of some of the 'sibling' asteroids are not precisely known either, making it hard to draw any definite conclusions regarding a shared origin.