Figure 2. Yearly whole-Earth mass flux per decade of particle mass. The different lines are described in the text.

by evenly distributing them into the 3 mass decades below the maximum, our numbers (curve c) in Figure 2 are in better agreement with those of Ceplecha et al. For lack of a better approximation we distributed all these events in the top three decades. The reason why these events do not show deceleration remains unclear. This question along with approaches to better determine deceleration and thus BP/mass is under current investigation.

In Figure 2 we note two mass limits of considerable interest. The upper limit is simply determined by the small area of the 300 m diameter AO radar beam [4] for which incidence of particles larger than 10-7 kg is quiet improbable. The lower limit, is that of so-called /3-meteoroids [5] that should not reach Earth from outside Earth's orbit. Interestingly, the flux observed falls off much more quickly than the Ceplecha et al. results as this limit is approached. It remains to be seen if this trend will be sustained as we continue to add to our database.

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