Electric Fields and Waves in the Venus Nightside Magnetosphere

Area of Science:

• Planetary Science
• Space Physics
• Plasma Physics

Background:

• The Venusian magnetosphere's nightside is poorly understood due to measurement challenges.
• Previous studies primarily focused on magnetized bodies, leaving gaps in understanding interactions with unmagnetized ionospheres.

Purpose of the Study:

• To conduct the first accurate electric field measurements within the nightside Venusian magnetosphere.
• To investigate wave phenomena and plasma interactions during a Parker Solar Probe Venus flyby.

Main Methods:

• Utilized the Parker Solar Probe's electric field antennas with a novel current biasing technique in Venus's shadow.
• Collected approximately one minute of electric field data during an eight-minute nightside magnetosphere crossing.

Main Results:

• A few Hertz, purely electrostatic signal was the primary observation in the nightside magnetosphere.
• Minimal electromagnetic waves, such as low-frequency turbulence or whistlers, were detected.
• The sunlit flanks exhibited numerous electromagnetic wave modes.

Conclusions:

• The findings suggest solar wind interaction with unmagnetized bodies like Venus differs significantly from magnetized bodies.
• A new algorithm for biasing electric field antennas in solar shadows was developed, improving accuracy.