Ziggy played guitar, and scientists in the UK were playing with a large piece of dry ice to try to figure out what was behind the strange alien patterns known as the “spiders on Mars. “
These patterns, which are visible on satellite images of the south pole of the Red Planet, are obviously not real spiders; but the branching, black shapes carved into the Martian surface appear creepy enough that researchers call them “araneiforms” (meaning “spider-like”) after discovering the shapes more than two decades ago.
The giant shapes, which are up to 1 kilometer wide, do not look like anything Earth. But in a new study published in the journal on March 19 Scientific reports, scientists have successfully recreated a reduced version of the spiders in their laboratory, using a plate of carbon dioxide ice (also called dry ice) and a machine that simulates the Martian atmosphere. When the cold ice made contact with a much warmer bed of Martian sediment, a portion of the ice immediately transformed from a solid to a gas (a process called sublimation), which formed spider web cracks where the escaping gas pushed through the ice.
“This research presents the first set of empirical evidence for a surface process that is likely to change the polar landscape. March, “lead author Lauren McKeown, a planetary scientist at the Open University in England, said in a statement. “The experiments directly show that the spider patterns we observe from an orbit on Mars can be carved by the direct conversion of dry ice from solid to gas.”
The Martian atmosphere contains more than 95% carbon dioxide (CO2), according to NASA, and so much of the ice and frost that forms around the poles of the planet in winter is also from CO2. In a 2003 study, researchers hypothesized that the spiders on Mars could form in spring when sunlight penetrated the translucent layer of CO2 ice and heated the ground beneath it. That heating causes the ice to sublimate from its base and build up pressure under the ice until it finally breaks. Refilled gas escapes through the cracks in a spraying plume, leaving behind the zigzagging spider cartridges visible on Mars today, the team assumed.
Until recently, scientists had no way of testing the hypothesis on Earth, where atmospheric conditions differ greatly. But in the new study, researchers made a small piece of Mars here on earth using a device called the Open University Mars Simulation Chamber. The team placed sediment grains of different sizes in the room and then used a system that looked like a claw machine you would see in a local arcade, to hang a block of dry ice over the grains. The team adapted the room to mimic the atmospheric conditions of Mars and then slowly dropped the dry ice block onto the grains.
The experiments proved that the hypothesis of spider sublimation is valid. Regardless of the size of the sediment grains, the dry ice is always sublimated when it comes in contact with them, and the escaping gas pushes upwards and tears spider-like cracks along the way. According to the researchers, the spider legs branch more if the grains were finer and less if the grains were coarser.
Although not definitive, these experiments provide the first physical evidence that shows how the spiders formed on Mars. Is not it so exalted?
Originally published on Live Science.