Washington: A team of researchers used rainbow-like light phenomenon observed on Venus cloud tops to identify the components of the planet`s acidic cloud cover.
The data was obtained by ESA`s space probe Venus Express. The data imply that the sulfuric acid in Venus` cloud tops could additionally contain pure sulfur or iron chloride - and may help solve one of the oldest mysteries of Venus research.
The veil of clouds surrounding Venus is as beautiful as it is hostile to life. Sulfuric acid constitutes their main component. Together with the planet`s dense atmosphere composed mainly of carbon dioxide, this cloud cover causes Venus` extreme greenhouse effect. Temperatures of more than 400 degrees Celsius are common on the planet`s surface.
The exact composition of the creamy-yellow clouds is still unclear. Almost 90 years ago, ground-based observations had shown that these clouds "swallow" ultraviolet light of certain wavelengths. Sulfuric acid alone cannot be responsible for this effect.
The list of possible candidates for the unknown substance is long: for example hydrobromic acid, amorphous sulfur, gaseous chloride and even bacteria have been suggested. But no one substance could be identified with certainty. Now, the glory spotted in the data of venus -express.html"> Venus Express`s Venus Monitoring Camera may offer help.
The most important precondition necessary to observe a glory is the observing position, explains Dr. Wojciech Markiewicz from the MPS, first author of the new study.