The Walls of Planet Three

On this wild planet, in its seas and sand,
forests and ice, lie ruins of perverse
attempts to overrun the universe:
the crumbling walls of failed human command —
Hadrian’s, China’s, Texas, Jerusalem —
fallen, decayed, functionless, desolate,
with scribbled mentions of their fears and hate:
Rivera... Pyramus.. Pink Floyd... Berlin...
their stones — cut, mined and blasted — left land bare,
leave plants still struggling over gouge and groove.
Planet-fall’s made, but no one dares to remove
their helmet in this dangerous atmosphere.
Infections lurk in water, air and ground;
walls’ poisoned Keep Out signs are all around.