Venus is known as a beautiful and bright planet. But, until recently, we hadn’t even seen it in the good light.
In July 2020, the Parker solar probe took the very first images of the Venusian surface in full visible light. It took a similar set of images during a flyby in February 2021. Now, astrophysicists have finally analyzed those visuals to get a better idea of the planet’s cloudy atmosphere and shrouded landscapes.
In the report, which has just been published in Geophysical Research Letters, a team from Naval Research Laboratory, Johns Hopkins University and NASA’s Goddard Space Flight Center described two types of light picked up by the probe: surface and nightglow. Surface glow comes from hot minerals on Venus’ terrain, while nightglow is emitted by gaseous molecules in the air. The suit gives the planet a halo-like ring that is visible to humans (if they ever flew too).
[Related: Something is making Venus’s clouds less acidic]
“The surface of Venus, even on the night side, is about 860 degrees Fahrenheit,” Brian Wood, an astrophysicist at the Naval Research Laboratory, said in a NASA statement. “It’s so hot that the rocky surface of Venus glows visibly, like a piece of iron from a forge.”
Parker’s February images were also the first to fully capture the planet’s surface on its night side. In the process, its cameras detected a wider range of light wavelengths, including some of the infrared spectrum. All together, the visuals help confirm previous observations from missions like Venera 9 in the 1970s, Magellan in the 1990s and Akatsuki in 2016. The new analysis concludes that previous temperature readings and topographic maps for Venus are more or less less correct. But the flyby images also explain a long-held legend about the “Morning and Evening Star” – the name some skywatchers use for the planet.
“There have in fact been numerous reports of weak emissions from the Venusian night side by credible amateur and professional astronomers, dating back to the 1600s,” the authors write in the paper. “This so-called ‘sharklight’ phenomenon, however, has never been successfully photographed, suggesting that the phenomenon may be an optical illusion.”
But amateur and professional astronomers should still look up into the skies to see Venus twinkle, the authors suggest. “The excellent dynamic range of the human eye might give the eye an advantage over electronic detectors in discerning something very faint near something so bright, but only repeatable images can provide truly convincing detection. “, they write in the study.
Parker will conduct three more flybys of Venus by November 2024 (although only one will be on the night side). NASA’s Davinci and Veritas missions are also on the agenda, which will carry a similar set of imaging tools capable of detecting a wide range of wavelengths.