How could astronauts have produced footprints on the moon if there wasn't any moisture in the lunar dust?

Consider your experience walking on a beach. When you walk near the water, where the sand is wet, your feet leave clear impressions in the sand. When you walk in dry sand, your feet tend to sink into the sand a bit further and leave little valleys in the sand. So, if the lunar surface is made up of a dry, sand-like material, how were astronauts able to leave footprints? Does this imply that the footprints must have been made on Earth?

The answer is that the moon's surface is simply not like sand. The lunar surface consists of a very fine powdery substance. The silicates that make up the lunar surface easily bond with other atoms and molecules, allowing the material to bond without water or moisture (Bara).

You can easily do an experiment to convince yourself that such substances exist:

Get some flour and spread it out on a flat surface. Make an impression in the flour with your shoe or hand or some other object and note the results!