Large meteoroids on minor cometary streams : recent events detected by the Spanish fireball network

Abstract

F. L. Whipple first modeled the forma-tion of meteoroid streams from the continuous subli-mation of the ice-rich regions in cometary nuclei [1,2,3]. Particles lifted off from ice-rich regions by the sublimated gas drag should be biased towards those fragile aggregates. Many cometary meteoroid streams crossing the Earth were formed in this way, but not all. Catastrophic disruption of cometary nuclei is another mechanism of producing meteoroid streams [4, 5, 6, 7]. Interestingly, this mechanism is able to produce large boulders as observed e.g. during the disruption of comet C/1999 S4 LINEAR [8]. It was believed that the large fragments released during break-up events will proceed to faint into the coma due to suffer a cascade fragmentation. The resolution of telescopic observa-tions is not able to decipher if the final product of these events are mm- or m-sized meteoroids. Fortu-nately, we can use fireball observations from known meteoroid streams to find out if large meteoroids are able to survive. We describe here one bright bolide that flew over many of the instruments operated by the SPanish Meteor and Fireball Network (SPMN) so that measurements of its properties were obtained.