Fragmentation of Meteoroids

Abstract

We have already mentioned repeatedly the great significance of the fragmentation of meteoroids (see Sections 20, 31, and 34). Now let us consider the main observational data attesting to this phenomenon [194]:

• (1) a high rate of ablation and, as a result, shorter trajectories and higher fadeout altitudes than are to be expected from the classical theory for individual bodies with a given initial photometric mass; this phenomenon, observed in 1946 for Draconids, led both to the dustball hypothesis (Section 33) and to the conclusion that fragmentation is important [352];

• (2) a higher maximum brightness than is predicted by the classical theory;

• (3) a difference between the shapes of the observed and theoretical light curves of meteors;

• (4) the presence on meteor light curves of irregular fluctuations, rapid rises in brightness, on various sections of the trajectory;

• (5) a difference between the dynamic and photometric masses of meteoroids (Section 34);

• (6) a separation of meteors into several parts (fragments), observed directly on photographs, especially those taken by instantaneous exposure [13];

• (7) a blurring of shutter breaks on photographs, particularly of faint meteors;

• (8) fragmentation in the air of meteorites reaching the earth’s surface.