ESA said their Mars Express captured the images of the “spiders” and explained that they are actually not creepy crawlies of any kind, but they are caused by carbon dioxide deposits.

Images taken by ESA's Mars Express orbiter and ExoMars Trace Gas Orbiter show dark clusters of dots that appear to have teeny little legs, not unlike baby spiderlings huddling together.

We take from La Nature the annexed engraving of the planet Mars and its second satellite, as the same appeared through the great telescope at the observatory of Paris, at 10:15 P.M., on August 37 ...