In:
International Astronomical Union Colloquium, Cambridge University Press (CUP), Vol. 85 ( 1985), p. 105-111
Abstract:
The in situ dust detectors on board the Helios spaceprobes detected impacts of micrometeoroids between 0.3 AU and 1 AU distance from the sun. Among the measured quantities were mass, impact speed and flight direction of the dust particles. Radial variations of the flux, azimuthal distribution and impact speed are discussed. Significantly different results were obtained for the “apex” particles observed by both ecliptic and south sensors and for the “eccentric” particles detected only by the south sensor. The radial spatial density variation of the “eccentric” particles is compatible with that derived for zodiacal light particles. Whereas the spatial density of “apex” particles peaks at 0.5 to 0.6 AU. From the measured quantities probability distributions of orbital elements were derived for the observed micrometeoroids. About 60% of the observed micrometeoroids (“apex” particles) are on low energy orbits (a ≲ 0.6 AU). About 30% of the particles (“eccentric” particles) had high energy orbits (a ≳ 0.9 AU). More than 10% of the observed particles show high probabilities for travelling on hyperbolic orbits.
Type of Medium:
Online Resource
ISSN:
0252-9211
DOI:
10.1017/S0252921100084438
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1985
