EVOLUTION OF COMET-LIKE ORBITS OF METEORITE- PRODUCING GROUPS AND THEIR PARENT BODIES

Анотація

This paper presents the results of the study
of evolution of Jupiter-family comet-like orbits of six
meteorite-producing groups, including sporadic fireballs
from the IAU MDC database 2007 [1], sporadic meteors
from the SonataCo database [2], instrumentally observed
H5 and L3.5 ordinary chondrites, as well as near-Earth
asteroids which are potential parents of the examined
groups. In order to verify the relationship between
meteorite-producing groups and their potential parents, we
performed backward numerical integration of the orbital
motion of these groups’ members over several millennia.
The numerical integration was carried out using the Halley
software [3]. The equations of motion factored in
gravitational perturbations due to the major planets,
radiation pressure effects and the Poynting-Robertson drag.
The equations of motion were numerically integrated using
the 11 th -order Everhart method applicable to studying the
motion of Jupiter-approaching short-period comets. The
numerical integration of the mean orbital elements of a
group, as well as those of the relevant meteorite and
potential parent asteroid, over 5,000 years has shown that
the respective perihelia, eccentricities and arguments of
perihelion evolved in a similar manner over the specified
period. The D SH -criterion of Southworth and Hawkins [4],
which is a quantitative measure of orbital similarity, has
remained below 0.3 [5] for about 5,000 years in the groups
of Neuschwanstein and Mason Gully meteorites and for
about 3,500 to 4,500 years in the groups of Benešov and
Park Forest meteorites. In the groups of the Košice and
Pribram meteorites, the mean orbits and those of their
potential parents remained similar as defined in terms of the
D SH -criterion over a relatively short period of about 2,000
to 3,000 years. We can infer from our findings that
meteorite-producing sporadic fireballs and sporadic
meteors are related to the H5 and L3.5 ordinary chondrites
and their potential parents, i.e. near-Earth asteroids, in the
investigated groups. The estimated time intervals, over
which the evolving orbits of the groups’ members have
shown good similarity, are indicative of relatively recent
formation of meteorite-producing groups as a result of
fragmentation of their parent bodies.