The famous spiders that are trending on the Internet are dark cracks in the Martian ground, more commonly known as “araneiforms.” Recent images from the European Space Agency suggest that there are spiders on the Red Planet, but before we get too excited, let’s clarify what they are. Spiders on Mars are possible due to the sublimation of surface CO2 ice, which creates these patterns in the Martian sand. The patterns have radial arms resembling plant roots.
Esa Orbiter Detects “Spider Signals” on Mars
At first glance, it might seem that spiders are invading Mars, but there’s no need to be alarmed, especially if you fear these arachnids. The new images of Martian “spiders,” captured by the Mars Express orbiter and the ExoMars Trace Gas Orbiter from the European Space Agency (ESA), actually show seasonal eruptions of carbon dioxide gas on the Red Planet. Clustered around Mars’s southern pole, they’re called “spiders of Mars” because of their distinctive spider-like shape, but they form when carbon dioxide gas is heated by sunlight and breaks through layers of overlapping ice. It’s common to see them during this season.
These dark extraterrestrial spiders form at the beginning of each Martian spring when sunlight hits the layers of carbon dioxide deposited during the dark winter months. The gas jets that emerge, loaded with dark dust, break through ice layers up to a meter (three feet) thick before falling back and settling on the surface. This creates distinctive dark, spider-shaped splotches between 150 and 3,000 feet wide that can be seen in images from space probes. The araneiforms were first observed more than 20 years ago, but it wasn’t until 2021 that astronomers demonstrated exactly how they form.
Thanks to these studies, the orbiter continues to capture images of Mars’s surface daily, mapping its minerals, exploring the composition and circulation of its atmosphere, probing beneath its crust, and studying the Martian environment.
This story was written in Spanish by Perla Vallejo in Ecoosfera.
