The orbit of the Dhajala meteorite

Abstract

Observations of the trail caused by the meteorite which fell around Dhajala, Gujarat (India), on 28 January 1976 have been used to compute the probable orbit of the meteoroid in space. The cosmic ray effects in the meteorite fragments indicate high mass ablation (≥ 90%), suggesting a high velocity (≥ 20 km/sec) of entry into the Earth's atmosphere. The atmospheric trajectory is reasonably well documented and its deviation from the projected ground fallout can be understood in terms of the ambient wind pattern. The apparent radiant of the trail was at a point in the sky with right ascension 165° , declination +60°. Considering the errors in estimating the radiant, we get a range of orbits with a = 2.3 ± 0.8 AU, E = 0.6 ± 0.1, and ι = 28 ± 4° with the constraints of a ≥ 1.5 AU and V_∞ < 25 km/sec (which causes nearly complete evaporation of the meteoroid). Taking V_∞ = 21.5 lm/sec as indicated by the measured mass ablation of the meteorite, the orbital elements are deduced to be a = 1.8 AU, E = 0.59, l = 27°.6, ω = 109°.1, Ω = 307°.8, and Q = 0.74.