The episode is set on an Earth colony in the future.

You think twenty years from now there'll be Earth colonies out this far?

As your own legends hint, you yourselves are descendants of an Earth colony.

It used to be a big Earth colony.

If there was indeed a retrogressed Earth colony, it had retained some technology.

"However, this is an Earth colony and your citizens have rights."

And they were the remote descendants of an Earth colony.

The crew begins studying the planet to see if it's suitable for a possible Earth colony.

The same is true for all Earth colonies, of course.

A girl he had dated for a while had gone there to help establish an Earth colony.