The mystery behind bizarre alien-like patterns that resemble spiders on Mars has been solved.
There has long been questions over why the patterns, known as spiders from Mars, emerged on the red planet, with researchers at Trinity College Dublin finally providing answers.
In a recent study, researchers have provided the first physical evidence the patterns on the planet's surface are formed when carbon dioxide (CO2) ice solids are transformed into a gas.
The spider-like shapes are not found on Earth, and researchers say the patterns are etched into the surface of the planet when dry ice hits it and temperatures change ice immediately from a solid to a gas, also known as sublimation.
"Unlike Earth, Mars' atmosphere comprises mainly of CO2 and as temperatures decrease in winter, this deposits onto the surface as CO2 frost and ice," a statement from the Trinity College Dublin says.
Researchers from Trinity College, Durham University and the Open University conducted a number of experiments to recreate the patterns and found they were formed by dry ice sublimation.
"The experiments show directly that the spider patterns we observe on Mars from orbit can be carved by the direct conversion of dry ice from solid to gas," lead study author Dr Lauren McKeown said in a statement.
With Mars' atmosphere made up of about 95 per cent CO2, there is gas present in ice that forms around the planet.
That means when it is heated as it settles on Mars' surface, a pressure build-up can form cracks.
Gas escaping through those cracks is what leaves behind the pattern resembling spiders, tree branches and lightening strikes.
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