Orbit, emission spectrum, and photometric analysis of two [...] fireballs (Madiedo et al.)

Vol. 555
In section 10. Planets and planetary systems

Orbit, emission spectrum, and photometric analysis of two flickering sporadic fireballs

It has been estimated from collected meteorites that every million square km of the Earth's surface receives 36 to 116 meteorites over 10g every year (Bland et al. 1996, MNRAS, 283, 551). However, it is generally impossible to know where in the solar system these came from. Routinely analyzing the composition of falling meteors and tracing their origin, and ideally linking those to specific meteorite falls, would open up new probes of the structure of asteroids and comets and of the origin of the solar system. Madiedo et al. report the discovery and careful analysis of two very bright, flickering meteors that were observed by the Spanish Meteor Network in 2012. Their spectral analysis shows that both had a mostly chondritic composition. The flickering of the lightcurve probably reflected the rotation of the meteoroids. From the lightcurves and trajectories, they determine that one, named "Fuencaliente", had an asteroidal origin and an initial mass of ~200kg. The other, "Sevilla", most probably originated an old Jupiter-family comet with a 9AU periapse, and had an initial mass of ~4kg. The two bodies were predicted to have survived as meteorites, but due to their low predicted weight (~50 and ~10g), no search was attempted. Routine monitoring of such events over Spain (half a million square km) and elsewhere could lead to the discovery of key meteors and even meteorites in the future.