These two paintings are by the American painter and illustrator Michael Whelan (born in 1950). He is a well known science fiction and fantasy illustrator who produced hundreds of book covers. Like many artists in this business he knows quite well to use ruins and decay in his work.
I've seen things you people wouldn't believe.
Attack ships on fire off the shoulder of Orion.
I watched C-beams glitter in the dark near the Tannhauser gate.
All those moments will be lost in time, like tears in rain.