The Moon is lacking the basic ingredients of life, therefore it will never be a world with life.

For any manned colony in space, the elements of oxygen, carbon and nitrogen are essential to life.  These elements are common on Mars.  This directly means Mars is a plausible site for manned colonies.  It is also why the Moon is not a plausible site.   It seems possible to grow crops on Mars, because dirt could be created from available elements for the crops to grow in.  This cannot be done on the Moon.  Oxygen is one of the most common elements on the Moon, but it is always attached to other things in molecules – for example, it may be attached to iron, aluminum, or titanium, three of the metals found on the surface.

Now it may be argued “But the Moon is the closest world, so it’s the easiest to get to!”  Actually the energy requirements, the amount of rocket fuel required to put one kilogram on the lunar surface, is higher than that required to put one kilogram on the surface of Mars.

At the best, lunar stations would resemble our Antarctica research stations, and require extensive support and lifting of supplies from Earth.  Since all closed habitats lose their gases when airlocks are opened and closed, as well as through other means, a fair amount of resupply would naturally involve supplying carbon, oxygen and nitrogen.

There has been some recent hope that the findings of water and possibly other volatile elements and compounds at the lunar poles may change this reality.    To a degree this is true, but only to a degree.

We don’t have any idea how to mine in conditions approximating absolute zero, or how to operate machinery in such conditions.  We don’t know how to extract ice from the depths of a crater within a crater at the lunar North Pole, let alone move it to where people might have a habitat.  Think in terms of traversing twenty to fifty kilometers across the Grand Canyon.

It would be equally impossible  with a mechanized transport system such as a railroad, or lowly pack mules.  Ice and volatiles in the deep craters of the poles does is not actually an enabling mechanism for populating the Moon with colonies of humans.