Earth Planets Space, Vol. 50 (Nos. 6, 7), pp. 555-567, 1998
NASA/Ames Research Center, Mail Stop 239-4, Moffett Field, CA 94035-1000, U.S.A.
(Received January 5, 1998; Revised March 12, 1998; Accepted March 13, 1998)
Abstract: Zodiacal dust evolves from cometary debris through a stage called a meteoroid stream. Meteoroid streams produce meteor showers if a node of the stream is near 1 AU. On occasion, Earth encounters a stream of meteoroids that has not dispersed wide enough to be detected annually. A rare and often short lived enhancement of rates is observed during which the meteors typically have smaller radiant dispersion and sometimes anomalous fragmentation properties and end heights. Here, we summarize recent observations of these meteor outbursts and discuss how the results constrain our knowledge of the early stages of meteoroid stream formation. These stages tie meteoroid streams to cometary dust trails and are an important step in the dynamical evolution from cometary to zodiacal dust.