Lightning in the atmosphere of Venus is either ubiquitous, rare, or non-existent, depending on

how one interprets diverse observations. Quantifying when and where, or even if lightning

occurs would provide novel information about Venus’s atmospheric dynamics and chemistry.

Lightning is also a potential risk to future missions, which could float in the cloud layers (~50–

70 km above the surface) for up to an Earth-year. Over decades, spacecraft and ground-based

telescopes have searched for lightning at Venus using many instruments, including

magnetometers, radios, and optical cameras. Two optical surveys (from the Akatsuki orbiter and

the 61-inch telescope on Mt. Bigelow, Arizona) observed several flashes at 777 nm (the

unresolved triplet emission lines of excited atomic oxygen) that have been attributed to lightning.

This conclusion is based, in part, on the statistical unlikelihood of so many meteors producing

such energetic flashes, based in turn on the presumption that a low fraction (< 1%) of a meteor’s

optical energy is emitted at 777 nm. We use observations of terrestrial meteors and analogue

experiments to show that a much higher conversion factor (~5–10%) should be expected.

Therefore, we calculate that smaller, more numerous meteors could have caused the observed

flashes. Lightning is likely too rare to pose a hazard to missions that pass through or dwell in the

clouds of Venus. Likewise, small meteors burn up at altitudes of ~100 km, roughly twice as high

above the surface as the clouds, and also would not pose a hazard.