The Rover and The Retriever

Centuries after humans have died out, and the sun is dying. A Mars rover who never made it to its destination roams the earth alone, observing its surroundings and living its life to the fullest as it waits for the inevitable. The earth grows colder with every minute, but Rover stays. Until he meets another friend, one that should have gone extinct when the humans did, but dogs always were resilient, especially Golden Retrievers.
Read as the two unlikely companions grow to be the best of friends, silently communicating, acting in an understanding to each other, as they live their last days to the fullest.