07 July 2011

Asteroid 2002NY40 as a source of meteorite-dropping bolides / next round 2038-Feb-11 02:09

Asteroid 2002NY40 as a source of meteorite-dropping bolides
Josep M. Trigo-Rodr´ıguez, Esko Lyytinen, Daniel C. Jones, Jos´e M. Madiedo, Alberto J. Castro-Tirado,
Iwan Williams, Jordi Llorca, Stanislav V´ıtek, Martin Jel´ınek, Blanca Troughton, and Francisco G´alvez


A B S T R A C T
The existence of asteroidal meteoroid streams capable of producing meteorite-dropping bolides
has long being invoked, but evidence is scarce. Recent modelling of previously reported associations suggests that the time-scales to keep the orbital coherence of these streams producing
meteorites are too short. We present an unequivocal association between near earth object
(NEO) 2002NY40 and at least one bright fireball detected over Finland in 2006 August. Another two additional fireballs recorded from Spain and Finland seem to be related, together
producing a fireball-producing stream (β Aquarids). On the basis of historical data, the 2006
finding suggests the existence of a meteoroid complex capable of producing meteorites. Taking
into account present time-scales for orbital decoherence, if 2002NY40 has large meteoroids
associated with it, such behaviour would be the consequence of a relatively recent asteroidal
fragmentation. Supporting our claim, the heliocentric orbits of two recently discovered NEOs,
2004NL8 and 2002NY40, were found to exhibit a good similarity to each other and also to the
orbits of the three bolides. The fireball spectra of the two Finish bolides showed that the chemical abundances of these objects are consistent with the main elements found in chondrites.
This result is consistent with the probable Low iron, Low metal (LL) chondritic mineralogy
of asteroid 2002NY40. Consequently, this asteroid may be delivering LL chondrites to the
Earth. Additional fireball reports found in the literature suggest that the associated β Aquarid
complex may have been delivering meteorites to the Earth during, at least, the last millennium.
Key words: meteors, meteoroids – minor planets, asteroids.

Mon. Not. R. Astron. Soc. (2007)
doi:10.1111/j.1365-2966.2007.12503.x

Whole Paper:
http://www.spmn.uji.es/ESP/articulo/2002NY40_MNRAS.pdf

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