Interplanetary and Interstellar Dust Observed by the Wind/WAVES Electric Field Instrument

Abstract

Observations of hypervelocity dust particles impacting the Wind spacecraft are reported here for the first time using data from the WindWAVES electric field instrument. A unique combination of rotating spacecraft, amplitude-triggered high-cadence waveform collection, and electric field antenna configuration allow the first direct determination of dust impact direction by any spacecraft using electric field data. Dust flux and impact direction data indicate that the observed dust is approximately micron-sized with both interplanetary and interstellar populations. Nanometer radius dust is not detected by Wind during times when nanometer dust is observed on the STEREO spacecraft and both spacecraft are in close proximity. Determined impact directions suggest that interplanetary dust detected by electric field instruments at 1 AU is dominated by particles on bound trajectories crossing Earths orbit, rather than dust with hyperbolic orbits