@Remus2
Water has been found in the Moon and in/on Mars. The estimated volume in either place is too little to support multiple millions of people, however it is enough to support a few hundred thousand.
Assuming you are correct. A few hundred thousand for how long?
But more practically, the reality is that the shear cost of transporting and maintaining even five hundred people on the moon is, excuse the pun, lunacy.
Even if a commercial venture was set up to mine 'unobtainium' on the moon, the cost would make it so expensive that the market for it would be far too small to make it viable.
It would be far cheaper to find an alternative than to extract, process and transport it back to earth.
Diamonds are expensive, so make cubic zirconia instead.
Those who argue against space exploration/colonization, are in effect arguing that the race of humans would be better off extinct.
Given the known lifespan of planets etc earth has a finite life, therefore if mankind survives that long, yes, we will become extinct, or burnt to a crisp as the earth approaches the sun, whichever description you prefer.
I think your argument is rooted in the throwaway mindset. Whilst some of us think that if we can't look after the planet we are on now, why would we ever think it possible for us to move on and succeed elsewhere?
If you think a colony on the moon mars or wherever could survive, you must already have solved all the multiple social issues that occur within any society. Or are you intent on an authoritarian culture where anyone not conforming is 'spaced'..? If you envisage multi generational settlement, have you solved the myriad requirements for childbirth, and kids, everything from nappies to how to deal with a teenager who looks at their computer, sees life on earth, contrasts it with a hermetic life eating kibble and decides they'd rather be on earth.
If you can't solve social issues here on earth, how long would a colony last given that it would only take a single act to cause a catastrophic failure.?
The "one giant leap for mankind" didn't survive budget cuts and administration changes. Given that any real attempt would take decades if not generations, does anyone really think that successive budgets and administrations would consistently 'stick with the plan' ??
Or course given the global economy forecasts, it might happen, but if you wanted to take part, you may need to learn Mandarin.