Effect of the Interplanetary Medium on Nanodust Observations by the Solar Terrestrial Relations Observatory

Abstract

Dust particles provide an important part of the matter composing the interplanetary medium; their mass flux at 1 AU is similar to that of the solar wind. Dust grains of nanometer size-scale can be detected using radio and plasma wave instruments because they move at roughly the solar wind speed. The high-velocity impact of a dust particle generates a small crater on the spacecraft: the dust particle and the crater material are vaporized. This produces a plasma cloud whose associated electrical charge induces an electric pulse measured with radio and plasma instruments. Since their first detection in the interplanetary medium, nanodust particles have been routinely measured using the Solar Terrestrial Relations Observatory/WAVES experiment [S/WAVES]. We present the nanodust properties measured using S/WAVES/Low Frequency Receiver [LFR] observations between 2007 and 2013, and for the first time present evidence of coronal mass ejection interaction with the nanodust, leading to a higher nanodust flux measured at 1 AU. Finally, possible influences of the inner planets on the nanodust flux are presented and discussed.