A Search for Meteoroid Streams and Their Sources in the Near-Sun Zodiacal Dust Cloud

The structure and dynamics of the zodiacal cloud close to the Sun may be significantly influenced by the interaction between a background quasihomogeneous zodiacal cloud and discrete meteoroid streams associated with small bodies like comets and asteroids. The extent of this influence depends upon how many such streams exist and the mechanisms by which they modify the near-Sun zodiacal cloud. This study compares in situ dust detection data in near-Sun solar wind against predictions made by a simplified zodiacal dust cloud model to search for small-scale meteoroid stream structures. A strong localized departure from the model is found. A small number of asteroids and comets have been identified that have orbits appropriate to produce the observed departure from the model through either direct meteoroid stream detection or through enhanced β-meteoroid production. These observations suggest that discrete meteoroid streams may be common in the inner zodiacal cloud and therefore may be important for its structure and dynamics.