It’s the concrete floor showing through where they staged this so-called “landing” 
Crop circles.
They are thinking ice, and I suppose that’s reasonable.
I wouldn’t be too surprised were it metal. 
–James
Oil leak.
Home plate.
I saw this on X-Files once. It’s actually the top of an alien space craft that was buried hurredly by gov’t forces attempting to keep us in the dark about visiting aliens who plan to eventually take over our planet.
Imagine it! Aliens on Mars! Gosh! 
djm
Isn’t that where the Oceanic six live? I don’t keep up with it but I thought there was something buried in the Martian landscape?
Anti-moles.
Top of pyramid left by Predators