Science

soothsayer

(38,601 posts) Tue Mar 30, 2021, 03:43 PM Mar 2021

First experimental evidence for the formation of 'Martian spiders'

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Universe Today
@universetoday
First experimental evidence for the formation of 'Martian spiders' - Universe Today https://universetoday.com/150709/mars-spiders-form-as-spring-arrives-on-mars-but-why/… by @AndyTomaswick featuring research by @mclaurenseries and @megafloods

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Mars Spiders Form as Spring Arrives on Mars. But why?

A person suffering from arachnophobia might think their fear would stoked on a trip to Mars. However, there is such a thing known colloquially as a Martian “spider”. It is much more innocuous than the eight legged animal that strikes fear into the hearts of millions, but its origins have only been theorized until recently. Now, a team led by a group at Trinity College Dublin has determined that these “spiders” are actually topological troughs formed when dry ice directly sublimates to a gas.

The “spiders”, or to give them their proper name, “araneiforms” have been known for some time. These spider-life features of the Martian terrain form in the spring, but are not known to form at all on Earth. Araneiforms have been captured by various satellites orbiting Mars for the last 20 years. Their transitory nature makes them particularly interesting to scientists looking to better understand Martian seasonality and weather patterns.

For a long time, there has been a theory about where araneiforms came from. That theory, known as Keiffer’s hypothesis, named after Hugh Kieffer formerly of the US Geological Survey, centered on the idea that the sun would cause the ground under blocks of dry ice to heat up, eventually sublimating the dry ice it is in contact with. Pressure would then build up in the ice block, eventually rupturing it and allowing the gas to escape. The quick escape of the gas then forms the dendritic pattern characteristic of araneiforms in the dust of the Martian surface.