Interplanetary and interstellar dust observed by the Wind/WAVES electric field instrument


  • The nature of the mechanism that couples the antennas to the impact generated plasma cloud is presently not understood. The previously proposed mechanism of charge recollection by the antennas is not a satisfactory explanation. Therefore, all the parts of the text concerning this mechanism have been removed. The particle size is now inferred by reporting the observed flux on a classical dust flux model : a paragraph explaining this point has been added to the section 4.


Observations of hypervelocity dust particles impacting the Wind spacecraft are reported here for the first time using data from the Wind/WAVES 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 Wind/WAVES at 1 AU is dominated by particles on bound trajectories crossing Earth's orbit, rather than dust with hyperbolic orbits.