The acid cloud wall moves at extremely high speeds, about 330 km/h, seemingly disappearing and reappearing randomly on Venus.
Amateur astronomer Luigi Morrone captured this image of a giant acid-filled cloud wall on Venus from Agerola, Italy. Newsweek The strange wall, called the Venusian Cloud Disruption, is about 8,000 kilometers long, cutting across the equator and hovering about 48 to 56 kilometers above the planet’s surface. The strange structure was first spotted by Japan’s Akatsuki orbiter, then disappeared and reappeared periodically. Morrone last saw it in 2022.
The Venusian Cloud Disruption is a wave-like structure moving westward. It can be seen by many spacecraft and ground-based telescopes in the visible and ultraviolet wavelengths. It moves at an extremely high speed, about 330 km/h, completing one orbit around the planet in about 5 Earth days, much faster than the time it takes Venus to rotate on its axis – 243 days.
According to NASA, the Venusian Cloud Disruption has likely existed since around the 1980s. Scientists are still unsure why the wall formed and how it moves so quickly around the planet. “This atmospheric discontinuity is a new meteorological phenomenon, never seen before on other planets,” said Javier Peralta, a scientist at the Japan Aerospace Exploration Agency (JAXA).
The strange wall is not always present, but seems to disappear and return randomly. “Note that this is not a permanent atmospheric phenomenon on Venus, but a ‘recurring’ phenomenon (like El Nino or La Nina on Earth), although we still don’t know how it forms or when it becomes apparent,” Peralta said.
Venus’ atmosphere rotates much faster than the planet itself, a phenomenon known as superrotation. “We suspect the Venus Cloud Disruption is a type of atmospheric wave (a Kelvin wave) because it travels faster than the superrotating winds and appears to dissipate before reaching the cloud tops. We think it may form somewhere below the clouds, carrying atmospheric momentum from the largest lakes on Venus to the cloud tops, where the fastest superrotating winds are,” Peralta explains.
Venus is the hottest planet in the Solar System, despite not being the closest to the Sun. The average surface temperature of Venus is around 465 degrees Celsius. This is because the planet has a very thick atmosphere, mainly composed of CO2, with a layer of sulfuric acid clouds about 48 – 64 km above the surface. This atmosphere means that the surface pressure on Venus is extremely high, about 92 times that of Earth.