If not due to a larger collecting area, this increase can be explained by other factors as follows. 1996), and the European Network's covering area of ~1 × 10 6 km 2 has not significantly changed (Oberst et al. The Prairie network in the United States (0.75 × 10 6 km 2 ) shut down in 1975, the Canadian Meteorite Observation and Recovery Project (MORP)-1.3 × 10 6 km 2-stopped observing in 1985 (Halliday et al. 2012), other major networks ceased operations. While the initial phase of the Desert Fireball Network (DFN) started science operations in December 2005, covering 0.2 × 10 6 km 2 (Bland et al.
2015), without a significant increase in collecting area of the major dedicated fireball networks. In the decade following 2000, the recovery rate of meteorites with determined orbits has dramatically increased (Borovička et al. Dedicated Networks to Recover Meteorites with Known Provenance In order to understand the origin of the different groups of meteorites from the main asteroid belt, it is therefore essential to collect several dozen samples with orbits and look at source regions in a broader, statistical way. 1994).Ĭalculating the orbit of a meteoroid using only the luminous trajectory as the observation arc is in most cases not precise enough to allow unequivocal backtracking into a specific region of the Main Belt, hence the statistical results reported by Bland et al. This can occur on a time scale of less than a million years in some cases (Morbidelli et al. If the debris field is close to a powerful resonance (in semimajor axis, inclination, eccentricity space), the breakup event feeds material into that resonance, which will in turn push the debris’ perihelia into the inner solar system. 1998) and as a consequence their semimajor axis is continually altered. The small members of the debris field can be strongly affected by the Yarkovsky effect (Farinella et al. The way this material evolves onto an Earth crossing orbit starts with a disruption in the Main Belt. From the instrumentally documented fall of the Příbram meteorite in 1959 (Ceplecha 1961), we learned that chondritic material comes from the asteroid Main Belt. However, aside from a handful of Lunar (≃300) and Martian (≃200) meteorites that have a well-known origin, the link with other solar system bodies is limited. This makes the connection of Dingle Dell to the Flora family (currently thought to be the origin of LL chondrites) unlikely.Īs of mid-2017, there are nearly 60k meteorite samples classified in the Meteoritical Bulletin Database. By numerical integration over 1 Ma, we show that Dingle Dell was most likely ejected from the Main Belt by the 3:1 mean motion resonance with Jupiter, with only a marginal chance that it came from the ν 6 resonance.
Dingle Dell is the fourth meteorite recovered by the DFN in Australia, but the first before any rain had contaminated the sample. The four person search team recovered a 1.15 kg meteorite within 130 m of the predicted fall line, after 8 h of searching, 6 days after the fall. Deceleration data indicated one large fragment had made it to the ground. The 30 cm meteoroid entered at 15.44 km s −1, followed a moderately steep trajectory of 51° to the horizon from 81 km down to 19 km altitude, where the luminous flight ended at a speed of 3.2 km s −1. The fireball was observed by six observatories of the Desert Fireball Network (DFN), a continental-scale facility optimized to recover meteorites and calculate their pre-entry orbits. We describe the fall of the Dingle Dell (L/LL 5) meteorite near Morawa in Western Australia on October 31, 2016.