I had this dream several years ago, but it bothers me a little bit, because of symbolism that I don't understand.

In a first scene, I'm on a hilltop on another planet. Snow and red dirt. No other content to that scene, but it is very lucid, and I can clearly feel the air and the feeling of the place.

In another scene I'm somewhere else on what I presume is the same planet. It has a dry climate, and cool air, but not cold, with a few pine-like trees. I'm stopping the truck at a road end at the edge of a canyon. I stop before a partially constructed layer of glass that's suspended about a foot above the road surface, and I feel like the location might be where the foot of a bridge would be.

I'm a policeman, driving a trailer truck, transporting a handcuffed prisoner. The back of the trailer truck is a metallic cylinder. There's a monster in the cylinder, and I hear it stirring. I free the prisoner, telling him that he's on his own.

In another scene the back of a cylindrical truck is open, and there's a man-eating worm-like thing inside.

In another scene, I'm inside some kind of large factory containing many cylinders.

In another scene, there's a sense of there having been an accident involving an exploding cylinder, I think. This memory has mostly faded.

The repetition of the cylinder image is unusual for me. Sometimes I'll dream of the same thing using two different metaphors that give different perspectives on it, but otherwise there is usually very little repetition in my dreams. I don't feel like I understand what the cylinder represents. My best guess afterwards was its a gigantic heroin needle, but I don't think that's it, at least not primarily.

The feelings in this sequence of dreams are very clear, but I don't seem to be able to connect them to anything in my waking life.

The thing that got me thinking about this again was the latest SpaceX launch failure, since a rocket is a cylinder also, and Musk introduced more ideas about traveling to mars at about that time. The dream feels closer to those images than it did to anything at the time I had it, but it is still not very close.

My dream planet is not mars, or at least not our mars, which is only about half the diameter of the earth and 1/10th the mass. I consider ideas of colonizing mars to be fanciful, the atmosphere is less than 1% as dense as ours. Mars feels to me like a stillborn planet. If it were larger, it would be about the right temperature to live on several hundred million years in the future from now, when the earth is getting too hot from the sun's life cycle. And it would have a lot more water, and an atmosphere. But it is not like that. My dream planet is bigger I think, more like what mars would be if mars wasn't too small. Even then I don't think it feels like mars though.

I can imagine the cylinder to represent a kind of judgmental thought. I think, for example, that people should be honest. My attitude about this is itself a kind of problem though. The metaphor sort of makes sense, but it still doesn't really click, the cylinder also represents something else more concrete than that.