The imposing cloud fronts that surround the surface of Venus are evident in ultraviolet (UV) light, in a sequence of images taken by the Akatsuki mission from the Japanese Space Agency (JAXA).
The video made avail by the Institute of Space And Astronautical Science shows a ‘synthesized pseudo-color animation of Ultraviolet Imager (UVI) onboard Venus Climate Orbiter, Akatsuki, with the 283-nm and the 365-nm filters.’
The video starts with data starting on November 16, 2018, and ends on December 7, 2018.
The time in the upper left shows the observation time in UTC, while the numbers in the lower left show the angle between the direction of the spacecraft seen from Venus and the direction of the sun. The altitude of the spacecraft can be found in the lower right part of the video.
The video and images reveal that clouds cover the entire planet and there is no trace of the surface of Venus under the clouds.
These clouds consist of sulfuric acid.
Clouds flow from right (east) to left (west) across the entire planet due to the existence of particularly strong winds, blowing at around 100 meters per second and called ‘super-rotation’ winds.
One of the purposes of Akatsuki is to investigate the mechanism of this phenomenon.
The video also shows evidence of a vast and darker region that has a strange V or Y shape, flowing westward as it changes its shape.
Its mechanism of formation of this pattern is still a mystery to scientists.
The color of the darker region varies with time, the reddish region includes a relatively large amount of sulfur dioxide and the reagent of the sulfuric acid clouds.
The bluish region includes a relatively large amount of the unknown absorber that causes a specific yellowish color of Venus.
According to a statement accompanying the video, at mid-latitudes, oblique streaks are seen.
These Venusian streaks seem to be created by elongated clouds slantwise. Clouds on Venus appear to be transported from the equator of the planet to its poles, however, northward/southward circulations with one cell for each hemisphere could not be seen in the Earth.
As the atmosphere of the planet transitions westwards, it extends northward and southward, and the fine-grained clouds appear to be more explicit.
These fine-grained clouds give off the impression that they are similar to cumulonimbus on Earth, however, a mechanism that explains these fine-grained clouds is still not well understood, reports JAXA.
This fascinating view is helping us understand Venus in an unprecedented way. A recent study also showed that Venus had a climate suitable for life, and vast oceans of liquid water covering its surface, billions of years ago.
But the gravity of the sun ‘pulled’ on the massive oceans on the surface and slowed down the rotation of planet and greenhouse gassed eventually formed thick clouds that heated the planet, according to NASA.