Spiders from Mars! This phrase describes both David Bowie’s support group in the 1970s and a special feature of Mars that has nothing like Earth. But we are here to discuss the latter, because scientists have experimental evidence of how they were formed.
In an article published in Scientific Reports, the researchers simulated the state of the Martian South Pole and discovered a process that creates araneforms, the spider-like feature observed in many orbital observations of the Red Planet. The team is testing Kieffer’s so-called hypothesis for their formation, which coincides with incredible observations from the last decade. And now it can be recreated correctly in the laboratory.
Mars is much cooler than Earth and its atmosphere is made up mostly of carbon dioxide. In the winter at the poles it freezes from the air on the ground and in the spring it sublimes ̵
Sunlight penetrates the transparent ice and warms the soil beneath it. The ice sheet will begin to sublimate closer to the ground, while the outer ice sheet will not be able to cope with the pressure and cracks, creating a special pattern in which the sandy / dusty material of Mars will be deposited as a plume.
“This study presents the first set of empirical evidence for a surface process believed to alter the polar landscape of Mars. Kieffer’s hypothesis has been well accepted for more than a decade, but so far it has been formulated in a purely theoretical context, “said lead author Dr. Lauren McCown of the Open University.
“Experiments show directly that the patterns of spiders we observe on Mars from orbit can be carved by directly converting dry ice from solid to gas. It’s exciting because we’re beginning to understand more about how the surface of Mars changes seasonally today. Dr. McCown continues.
The team had an ingenious approach to test this. They used a vacuum chamber to recreate the very low Martian pressure. They attached a perforated block of dry ice (frozen carbon dioxide) to a mechanical arm and lowered it to simulated soils made of grains of various sizes.
Located near the warmer soil, the block is sublimated by lifting the material in a loop through the central hole of the block of freshly separated gas. After the block was removed, an araneform structure was left on the soil. The finer the soil, the more branched the model.
“This innovative work supports the emerging theme that the current climate and weather on Mars have an important impact not only on dynamic surface processes, but also on any future robotic and / or human exploration of the planet,” explained co-author Dr. Mary Burke of Trinity. Dublin College.
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