So it's plausible that any planetary civilizations (alien or human) may have landfills. It is also natural to think that many planetary civilizations would die out, or migrate away from a planet. So in the event that a planet is abandoned, what would happen to landfills (if left alone) for:
- 1000 years
- 10,000 years
- 1,000,000 years
I'm going on the assumption that these planets are not subject to cataclysmic collisions (although meteor events may occur), and that a "year" equals one earth year.
Thank you landfill experts!