Mass distribution of massive meteoroids determined by occurrence of brilliant fireballs

It is stated that determination of the mass distribution function of celestial bodies is of paramount importance for an understanding of the evolutionary processes that determine the population of the Solar System. Values of the mass distribution index have been well established for meteoroids of mass 10-12 <= m <= 10 g and reasonable estimates are available for larger bodies such as meteorites and asteroids, but there is a lack of information for the mass range 10 <= m <= 105 g, corresponding to meteoroids that yield meteors of visual magnitude. A method is here reported for measuring the mass distribution of meteoroids by determining the occurrence of very bright fireballs. Here fireball refers to any meteor brighter than Venus. Whilst meteor counts over periods of hours at a single station are suitable for estimates of the mass distribution index for m <= 1 g, such a procedure yields a prohibitively low count for larger objects, a difficulty that could be overcome only be observing over a large area of the Earth's surface for many years. (U.K.)