It's very difficult for scientists and astronomers to directly study surface features on the planet Venus because of the thick cloud cover. That thick layer of clouds blocks satellites and telescopes from directly imaging the surface of the planet as satellites are able to do here on Earth. For decades scientists and astronomers have wondered whether or not Venus could have active volcanoes on its the surface.
New evidence hinting that there are in fact active volcanoes on the surface of Venus has been offered by the ESA Venus Express orbiter. The orbiter has detected major changes in the amount of sulfur dioxide gas above the thick and dense layer of clouds that covers the surface of the planet. Scientists say that the thick layer of clouds that covers the surface of Venus is composed predominantly of sulfuric acid droplets.
Wind speeds on the planet reach hurricane force near the top of the clouds circumventing the planet in only four days. This process is known as super-rotation. Scientists also know that the atmosphere is rich in carbon dioxide and is 90 times denser than the atmosphere on Earth. The thick layer of clouds and the dense atmosphere pushes the surface temperature on Venus to about 460°C.
In the past, radar imagery has shown over 1000 volcanic structures and evidence of resurfacing of the planet periodically by large quantities of lava. The latest evidence of volcanic activity on Venus comes courtesy of the Venus Express SPICAV-UV spectrometer. This instrument discovered an unusual change in the quantity of sulfur dioxide in the upper atmosphere.
When sulfur dioxide reaches the upper atmosphere of the plane, it is rapidly destroyed by solar UV light giving it a very short life of less than half a day in the upper atmosphere of Venus. Therefore, the scientists believe that for the concentration of sulfur dioxide in the upper atmosphere to increase significantly a much higher concentration of gas is being added to the atmosphere beneath the clouds by volcanic outgassing. If correct, this could be the first evidence of active volcanoes on the surface of Venus.
[via Space Daily]