Perspectives on Interstellar Dust Inside and Outside of the Heliosphere

Abstract

Measurements by dust detectors on interplanetary spacecraft appear to indicate a substantial flux of interstellar particles with masses exceeding 10^{-12}gram. The reported abundance of these massive grains cannot be typical of interstellar gas: it is incompatible with both interstellar elemental abundances and the observed extinction properties of the interstellar dust population. We discuss the likelihood that the Solar System is by chance located near an unusual concentration of massive grains and conclude that this is unlikely, unless dynamical processes in the ISM are responsible for such concentrations. Radiation pressure might conceivably drive large grains into "magnetic valleys". If the influx direction of interstellar gas and dust is varying on a ~10 yr timescale, as suggested by some observations, this would have dramatic implications for the small-scale structure of the interstellar medium.

13 pages. To appear in Space Science Reviews

References in corpus (5)

• Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
• Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample
• The Structure of the Local Interstellar Medium V: Electron Densities
• The search for the origin of the Local Bubble redivivus
• Interstellar Dust in the Solar System

Cited by in corpus (3)

• Modeling Porous Dust Grains with Ballistic Aggregates I: Geometry and Optical Properties
• Project Icarus: A Review of Local Interstellar Medium Properties of Relevance for Space Missions to the Nearest Stars
• Brilliant Pebbles: A Method for Detection of Very Large Interstellar Grains