Non-detection of lightning during the second Parker Solar Probe Venus
gravity assist
Abstract
The Parker Solar Probe (PSP) spacecraft completed its second Venus
gravity assist maneuver (VGA2) on 26 December 2019. For a 20 minute
interval surrounding closest approach, the PSP/FIELDS Radio Frequency
Spectrometer (RFS) was set to ‘burst mode’, recording radio spectra from
1.3–19.2 MHz at sub-second cadence. We analyze this burst mode data,
searching for signatures of radio frequency ‘sferic’ emission from
lightning discharges. During the burst mode interval, only 4 spectra
were observed with strong impulsive signals, and all 4 could be
attributed to saturation of the RFS high gain stage by
\emph{in situ} electrostatic plasma waves. These RFS
measurements during VGA2 are consistent with previous non-detection of
radio frequency lightning signals from Venus reported by Gurnett et al.
(2001).