Unexplained shapes seen on Venus, which some scientists have suggested could be signs of alien life, are even more mysterious than we thought.
Researchers studying the Venusian surface have found that the strange dark spots are affecting the planet's climate, after a new breakthrough study.
Scientists have known about the dark "splotches" on the surface for more than a century, and they change over time. But they have never been explained, with some researchers suggesting they could be evidence of life.
“The particles that make up the dark splotches, have been suggested to be ferric chloride, allotropes of sulfur, disulfur dioxide and so on, but none of these, so far, are able to satisfactorily explain their formation and absorption properties,” said Yeon Joo Lee, the senior author of the new report, in a statement.
Observations show that the particles in those dark spots seem to be the same size, and behave similarly to, the microorganisms that can be found in the Earth's atmosphere. Along with other evidence, that has led to some of the world's most famous scientists including Carl Sagan speculating that the shadowy patches could be life.
Now researchers have learnt more about how those clouds affect the climate on the planet.
The researchers looked for changes in the planet's "albedo", or how much it absorbs of the light that hits it. They found that it seemed to vary hugely: between 2006 and 2017, the amount of light being reflected back into space halved and then started rising again.
Those changes had a similarly large effect on the amount of solar energy that the clouds absorbed, and therefore how much ciculation there was in the planet's atmosphere. Vigorous activity could be seen in the planet's atmosphere, with clouds that whirled at more than 200 miles per hour, and could be explained by those changes in the clouds.
But, adding to the mystery, scientists still don't know why those dramatic changes are happening.
“That is a striking result,” Limaye adds. “It suggests that something is changing. We can see the change in brightness. If the albedo is changing, something is driving those changes. The question is, what is the cause?”
Those dark patches that have been the subject of so much speculation have been referred to as "unknown absorbers", and could play some role in those changes.
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