Orbital evolution of meteoroids from short period comets

We perform an accurate modelling of orbital evolution of dust grains taking into account both the ejection parameters derived from the analysis of the dust tail of each considered parent comet (Fulle 1989), and the integration of the Newton equations in the context of a nine–body problem (Sun, seven major planets and the dust particle) plus solar radiation and wind forces. Among Short Period Comets (SPC) we have selected P/Schwassmann–Wachmann 1 (P/SW1) and P/Griegg– Skjellerup (P/GS), which represent two significantly different objects from a dynamical point of view. Dust from P/SW1 is dominated by Jupiter perturbations: after 2 104 years, about 7% of the grains are ejected in hyperbolic orbits, 80% of the grains have the perihelion out of 4 AU from the Sun, and only 1% of them reaches the Sun distance of 1 AU, thus contributing to the inner zodiacal cloud. Dust from P/GS is dominated by the P–R drag, although large grains, due to their longer collapse lifetime, are sensitive to Jupiter perturbations. Therefore the Tisserand criterion represents a useful tool both to estimate the orbital evolution of grains larger than 100 μm (i.e. the most likely canditates to replenish the zodiacal dust cloud, Grün et al. 1985), and in distinguishing the parent sources of meteoroids collected with near Earth space experiments able to measure the impact velocity vectors. Jupiter perturbations oppose to the P–R drag forces and reduce significantly the contribution of SPC to the inner zodiacal dust: the simple sum of the dust mass contribution from each SPC may be an overestimate of their actual supply.