The Case for a Radio and Plasma Wave Receiver on an Interstellar Probe
Abstract
Any probe designed to explore the heliospheric boundaries and interstellar medium (ISM) should include a radio and plasma wave receiver. The Voyager Plasma Wave Science instrument discovered radio emissions in the frequency range of about 1.8 to 3.6 kHz that originate at and beyond the heliopause. The radio emissions are the result of shocks associated with global merged interaction regions or other solar transients that propagate through the heliosphere and result in shocks propagating through the local ISM. The radio waves are generated from electron plasma oscillations in the high density ISM found in the electron foreshocks of these shocks. The Voyager radio observations obtained within the heliosphere provided realistic distances to the heliopause as well as a remote measure of the ISM electron density. The subsequent detection of plasma oscillations provided highly accurate measurements of the plasma density in the ISM and evidence for the influence of solar transients well into the local ISM and an outward density gradient extending for some 10s of astronomical units from the heliopause. Using a dipole antenna with length much greater than the Debye length, quasi-thermal noise measurements could provide electron density and temperature estimates even in the absence of plasma oscillations. The plasma wave measurements also provide a means of detecting dust grains that impact the spacecraft at velocities of 10 km/s and greater.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSH33C3665K
- Keywords:
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- 2126 Heliosphere/interstellar medium interactions;
- INTERPLANETARY PHYSICSDE: 6015 Dust;
- PLANETARY SCIENCES: COMETS AND SMALL BODIESDE: 6224 Kuiper belt objects;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTSDE: 6285 Trans-Neptunian objects;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS