Predicting CO Cameron‐Band Auroral Emission at Venus Using VEx Electron Observations

Abstract Various types of auroral emissions have been observed at (partially) magnetized planets (e.g., Earth, Jupiter, and Mars). Auroral emissions have also been observed at Venus, an unmagnetized planet, by the Pioneer Venus Orbiter (PVO) and ground‐based telescopes. By applying a linear relation, this study predicts the possible CO Cameron‐band emission brightness at Venus using electron observations from Venus Express (VEx). Our results suggest that to produce the PVO observations, electron acceleration is not required as in the case of discrete aurorae at magnetized planets; rather, the magnetic access of precipitating electrons to the lower atmosphere is the more limiting factor for auroral occurrence. This study helps better understand how aurorae can occur at an unmagnetized planet, in contrast to magnetized planets. It also has implications for future Venus mission design: auroral imaging can serve as a remote sensing tool to characterize the magnetization state of the Venus nightside atmosphere.