Large meteoroids from the 2P/Encke complex : orbital data of 2010 taurids recorded in the framework of the Spanish fireball network

Abstract

Cometary disruptions are though to be an important source of Near Earth Objects (heareafter NEOs). A continuous monitoring of meteor showers from multistation networks on the ground allows to get valuable orbital information of large meteoroids producing fireballs. From such orbits can be established conections with the orbital elements of diferent asteroids or comets. In 2010 we started a program to get precise orbital information of very bright Taurid bolides in order to try to identify possible associations with members of the NEO population [1]. We have already identified some meteoroids that could be dynamically associated with some NEOs currently identified as members of the Taurid complex. This group of bodies is formed by about 20 NEOs that presumably formed by the fragmentation of a giant comet over the past 20-30 kyr [2-4]. Some of these bodies have orbital affinities to comet 2P/Encke, but recent studies have found other asteroids in Apollo-like orbits that can be good candidates to trace a progressive cometary disruption that at different stages as a by-product produced the Taurid meteoroid branches [3, 4]. It is important to remark that the NEOs associated with the Taurid meteoroid streams are presumably dark, as seems to confirm the spectral information obtained for the largests members (e.g. 16960 belongs to the B spectral class [5]). Consequently these bodies are among the most difficult and hazardous NEOs that remain to be discovered. In fact, the Tunguska object has been temptatively associated with the Taurid complex [6]. A recent paper also links the Earth’s intersection with the debris produced by the disruption of the cometary progenitor with a possible Palaeolithic extinction occurred around 12,900 BP [7]. Our orbital studies of Taurid meteoroids could also identify other members of the complex by using association criteria and backwards integration of their orbits. In fact we have found some Taurid complex members that are exhibiting orbits not directly linked with the two main branches. Obviously, having the Taurid complex some members with about 100 meters in diameter [4], we suspect of the existence of much more bodies in such a range of sizes not discovered yet. These objects could also produce meteorite-droping bolides in determinate favourable geometric circumstances [1].