In article "Muzz" writes:
How many years was it after Chris Columbus sailed the ocean blue
to the new world before Europe finally started to colonize?

Umm, minus thousand?

Colonization was old news by the time of Columbus - there had merely
been a slight hiatus after colonization of Europe had been completed,
then recompleted according to the new definitions of "habitable" or
"arable", then recompleted again...

Little of the overseas colonization that followed the discoveries of
Columbus or his Africa-circumnavigating predecessors was technologically
or politically new ground. The economics of overseas colonization were
a bit different from the colonization of Europe, of course, in the
sense that some initial colonies were profit-hunting efforts concentrating
on perceived sources of gold or spices. But there was plenty of good
old settling being done, too.

Colonizing Mars or the Moon would be qualitatively different in some
ways. For one, there would be no hope of profits nor of arable land -
it would be a red-ink project all the way. Prestige would be a prime
motivation, far more so than in post-Columbus overseas colonization
efforts. The forces driving the effort would not be related to
the sudden emergence of means, as they were in the overseas case:
just because an expedition could go to Mars would not immediately
and automatically make Mars attractive to anybody.

I could see a scenario where Mars is inhabited for prestige alone,
very rapidly after the initial expeditions, then abandoned for good
when nothing worthwhile can be achieved there. Or then a scenario
where colonists only follow after a long succession of expeditions
has finally managed to find something attractive enough for a
profit-pursuing enterprise to exploit. Initially, such an enterprise
would be largely automated, but ultimately a human colony would emerge
from the maintenance needs of the exploiting machinery, and grow from
there.

In neither case would colonizing by itself be black-ink business,
and truly special psychological forces would have to control the
colonizing process - idealism combined with sense of duty to one's
national pride, perhaps?

Timo Saloniemi