Since the moon doesn’t have an atmosphere,there’s no wind or water to erode or wash away the Apollo astronauts’ mark on the moon. That means their footprints, roverprints, spaceship prints, and discarded materials will stay preserved on the moon for a very long time. They won’t stay on there forever, though. The moon still a dynamic environment. It’s actually being constantly bombarded with “micrometeorites,” which means that erosion is still happening on the moon, just very slowly.