Evidence for the Existence of Groups of MeteoriteProducing Asteroidal Fragments
Abstract
The MORP camera network in western Canada observed 56 events which are associated with meteorites larger than 0.1 kg. An additional 33 Prairie Network (central USA) fireballs with published orbits were previously identified as the sources of meteorites of at least 0.25 kg. A comparison of the MORP orbits with each other and with the PN orbits, using the Dprime criterion of orbital similarity, exhibits a surprising number of small values. This suggests there are groups of related objects among the 89 events. This paper evaluates the probability of small values of Dprime arising by chance from a group of random orbits that has the distribution of orbital elements expected for meteorites. There is an excess of small values of Dprime among the 89 meteoritic objects over the expectation for random orbits and a marked excess of very small values. Four groups comprising a total of 16 objects account for this excess. These groups exhibit a preference for the larger masses of the population and a very strong concentration of perihelia just slightly inside the earth's orbit. Although it has been shown by others that gravitational perturbations will disperse earthcrossing streams in times that are much less than cosmicray exposure ages, the properties of the four groups suggest they may be streams of fragments that crossed the earth's orbit only recently.
 Publication:

Meteoritics
 Pub Date:
 June 1990
 DOI:
 10.1111/j.19455100.1990.tb00981.x
 Bibcode:
 1990Metic..25...93H
 Keywords:

 Asteroids;
 Bolides;
 Meteoroid Showers;
 Orbit Perturbation;
 Gravitational Effects;
 Orbital Elements;
 METEORITES;
 ASTEROIDS;
 FRAGMENTS;
 ORIGIN;
 SOURCE;
 METEOR SHOWERS;
 ORBITS;
 EARTHCROSSERS;
 DISTRIBUTION;
 ANALYSIS;
 CALCULATIONS;
 PERTURBATIONS;
 TIMESCALE;
 Lunar and Planetary Exploration; Asteroids;
 Orbital