This was a quickie, done in Vue in about an hour or so. It's a direct Vue render, there's no post-work (yes, even the distortion in the sun comes from the render...
Our sun is about 4.5 billion years old nowadays. By the time it reaches 10 billion years, it'll turn into a red giant, extending beyond the Earth's orbit and thereby burning our planet to ashes.
In this image I tried to depict the sun 1,5 billion years before that phase, when it's already big but not yet a red giant. The moon is shattered to pieces by some catastrophic event and forms a ring of debris around Earth.
I didn't try to be accurate at all nor did I aim at realism (what do I know about realism 4 billion years from now?). I aimed at a stylized look, for which I used a basic silhouette style and a basic color palette.
Regarding the lonely walker, there's a metaphorical interpretation, of which I'll not talk, of course. Regarding the physical interpretation and the basic question "how can a man be there 4 billion years from now?", there are various alternatives. I'm not much worried about this but I could think of an evolution of the ape or some other animal to bipedalism, or a time traveler, or an alien visitor or even, why not, man didn't change that much through this time (there's an incredible book "The long afternoon of Earth", taking place more or less at this time, where man isn't that different from today, he's only very small, if I remember correctly).
This is the second image I make around this theme. Here's the other one: fav.me/d2t4lsh