Abstract
There has been important understanding of the process by which a hypersonic dust impact makes an electrical signal on a spacecraft sensor, leading to a fuller understanding of the physics. Zaslavsky (2015), https://doi.org/10.1002/2014ja020635 showed that the most important signal comes from the charging of the spacecraft, less from charging of an antenna. The present work is an extension of the work of Zaslavsky. An analytical treatment of the physics of a hypersonic dust impact and the mechanism for generating an electrical signal in a sensor, an antenna, is presented. The treatment is compared with observations from STEREO and Parker Solar Probe. A full treatment of this process by simulations seems beyond present computer capabilities, but some parts of the treatment must depend on simulations but other features can be better understood through analytical treatment. Evidence for a somewhat larger contribution from the antenna part of the signal than in previous publications is presented. Importance of electrostatic forces in forming the exiting plasma cloud is emphasized. Electrostatic forces lead to a rapid expansion of the escaping cloud, so that it expands more rapidly than it escapes, and sometimes surrounds one or more antennas. This accounts for the ability of dipole antennas to detect dust impacts. Some progress toward understanding occasional negative charging of an antenna is presented, together with direct evidence of such charging. Use of laboratory measurements of charge to estimate size of spacecraft impacts are shown to be not reliable without further calibration work.
Original language | English (US) |
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Article number | e2020JA028415 |
Journal | Journal of Geophysical Research: Space Physics |
Volume | 126 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2021 |
Bibliographical note
Funding Information:The authors thank CDAweb and Antoinette Galvin, (University of New Hampshire) for particle density and particle pressure data. This work was supported by NASA grant NNX14AK73G, NASA contract NNN06AA01C, and Securian Financial.
Funding Information:
The authors thank CDAweb and Antoinette Galvin, (University of New Hampshire) for particle density and particle pressure data. This work was supported by NASA grant NNX14AK73G, NASA contract NNN06AA01C, and Securian Financial.
Publisher Copyright:
© 2021. American Geophysical Union. All Rights Reserved.
Keywords
- dust impacts
- hypervelocity
- impacts