Limb imaging of the Venus O₂ visible nightglow with the Venus Monitoring Camera

Abstract

We investigated the Venus O2 visible nightglow with imagery from the Venus Monitoring Camera on Venus Express. Drawing from data collected between April 2007 and January 2011, we study the global distribution of this emission, discovered in the late 1970s by the Venera 9 and 10 missions. The inferred limb‐viewing intensities are on the order of 150 kR at the lower latitudes and seem to drop somewhat toward the poles. The emission is generally stable, although there are episodes when the intensities rise up to 500 kR. We compare a set of Venus Monitoring Camera observations with coincident measurements of the O2 nightglow at 1.27 µm made with the Visible and Infrared Thermal Imaging Spectrometer, also on Venus Express. From the evidence gathered in this and past works, we suggest a direct correlation between the instantaneous emissions from the two O2 nightglow systems. Possible implications regarding the uncertain origin of the atomic oxygen green line at 557.7 nm are noted.

Parker Solar Probe Imaging of the Night Side of Venus

“…We attribute this to the optical O 2 nightglow. A similar rim of limb-brightened nightglow emission is seen in nightside images from the Venus Monitoring Camera (VMC) instrument on VEX using the VIS filter (roughly 480-600 nm), with no detectable emission from the disk (García Muñoz et al, 2013).…”

“…Instead, nightglow emission from optical O 2 lines has been detected, dating back to the Venera 9 and 10 missions (Krasnopolskii et al., 1977 ; Lawrence et al., 1977 ). Although observable from the ground (e.g., Slanger et al., 2006 ), the emission has been most extensively studied using spectra from the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board VEX, particularly at the limb where the emission is at its brightest (García Muñoz et al., 2009 , 2013 ; Migliorini et al., 2013 ). Besides the O 2 emission, nightglow from the atomic O I 5577 Å green line has also been frequently observed (Slanger et al., 2006 ), but this emission is highly variable, and was curiously never detected by VEX.…”

Mesospheric optical signatures of possible lightning on Venus

“…However, in spite of the Veneras, PVO and VEX impulsive low frequency radio wave detections in Venus, no optical emissions from the night side of Venus have been recorded so far to unambiguously reveal the existence of lightning on Venus. Moreover, no conclusive results have been obtained in the last 20 years from the different attempts to detect lightning activity in Venus using ground-based telescopes [Hansell et al, 1995, Krasnopolsky, 2006, García Muñoz et al, 2013.…”

Three‐dimensional modeling of lightning‐induced electromagnetic pulses on Venus, Jupiter, and Saturn

“…Later, in 1995, Hansell et al [1995 observed several flashes from Venus using a ground-based telescope. However, other attempts to confirm these transient optical detections originated from the atmosphere of Venus did not succeed [Krasnopolsky, 2006, García Muñoz et al, 2013. The japanese Akatsuki probe, orbiting Venus since December 2015, is equipped with cameras to detect fast 777.4 nm lightning emissions and slow nightglow intensity variations in the 557.7 nm atomic oxygen line from the venusian atmosphere [Takahashi et al, 2008, Peralta et al, 2016.…”