Described by scientists as araneiform structures, these spiders are actually nothing more than radially organized channels moving outward from a central depression. They form “when the seasonal layer of dry ice turns to gas in the spring and erodes the surface,” and to our knowledge is something that only happens on the Red Planet.
At times, these features can be some 3,300 feet (1 km) across, hence seen from the altitude of the HiRISE, they kind of look like huge spiders. Luckily, the same HiRISE camera is capable of zooming in a bit, and that’s how we got the pic we have here.
Snapped back in 2016, at the time when the Martian spider phenomenon on Mars was not fully understood, the photo shows an undisclosed region of the planet, where two of these spiders play in close proximity to each other.
The closeup shows how these things are nothing more that shallow holes in the ground that in the right light make up the bodies of the spiders, accompanied by radial channels that make up the creatures’ legs.
So, not that scary in this pic, but certainly frightening in this one, which appears to show an entire arachnid army charging the hills.