Why the Milky Way needs a dark field

From the planetarium car park you can see a few hundred stars on a clear night. From the field at Cutler Ridge you can see a few thousand, and the Milky Way is a bright band from one horizon to the other.

The difference is the glow of street lights scattered by the air. Astronomers grade it on the Bortle scale from 1, the darkest, to 9, a city centre. Town is about 7; the field is about 3 (sample).

That is why dark-sky nights happen at the field and near new moon: the Moon’s own light would wash out the faint sky as much as the town does.