I guess we could grow a bunch of wheat inside of it, then send it back to earth. If we're not treated well we could swap wheat for rocks. At least, that what Heinlein suggested.

children, you have to be pernamently there to raise them

It'd be cool as fuck.

Science doesn't really happen if we continually ask "Why do this?" Science happens when we ask "Why not do this?"

If we want to be a galactic civilization, we must first learn to live on worlds otherwise uninhabitable. The engineering challenges we must overcome to make that happen will give us the knowledge and experience we need to make it possible to expand past our solar system. This is a very long term advancent, and what we do today is what our offspring will do with ease.

Other than political roadblocks, the final roadblock to galactic expansion is FTL travel. We have theories on how to make it possible, but we are limited to the engineering and knowledge of our time now. Far future generations will be the ones to discover if and how to make it possible, but they need the foundational knowledge and experience of how to live in space.

In reality there isn't any real reason to have a permanent base on either.... especially Mars.

Rocket fuel. The moon is like the local gas station you stop at to top off the tank and get snacks before you hit the open road.

Neither place is close enough or has enough resources for more than a research base, and remotely operating robots on Mars would be a lot easier and safer.

It takes a few eggs out of our current basket and puts it into other nearby baskets, so as to avoid complete species failure if our original basket falls or gets dropped.

Not the most ideal solution, as we should really step out of our stellar neighbourhood to achieve lasting civilizational redundancy, but it’s far better than not taking any eggs out of the current basket at all.

Plus, incremental efforts in achieving civilizational redundancy always have better results than great leaps, both in terms of consistency as well as resiliency. Figuring things out a bit at a time is nearly always more effective than trying to solve everything all at once.

Google: Tescreal, Freedom Citys, Peter Thiel, Sam Altman, Elon Musk, Jeff Bezos etc. Basically there are several projects where they try to do unregulated research. Main idea seems to be to "survive" the end of our civilisation by living in Space or in the deep sea, enhance themselves (eg neuralink) , create General Artificial intelligence etc. Thiels Palantir is thought as defense mechanism by surveilling everyone. It all sounds like a big conspiracy theory, unfortunately it is not. Musk being responsible for Dodge, deregulating the US Governement was exactly one of these things. It was never about saving money. This is all a big rabit hole and you will get in a very bad mood readinfg about it.

https://en.wikipedia.org/wiki/TESCREAL

On the moon, I am guessing some sort of railgun facility. Designate a specific spot on Earth, and you can launch mineral packets to crash there for terrestrial harvesting. Mind, I can see horrific consequences if something goes wrong.

In an old game called Stars!, I used to prepare worlds via mineral deposits to serve as industrial centers. The process also conveniently cleared out the previous inhabitants.

The rest of creation: we have a perfect blue marble to live on in a void of deadly nothing. Humams: challenge accepted!

Exploration and discovery for humanitarian goals, different abundance of resources and lack of other resources usually gives opportunities for mining, production/refining/fabrication, and trade. And further, more metal resource rich regions like the asteroid belt will require developing the same tech needed to establish outposts, bases, and fueling stations far from earth.

the colonies have a right to exist without OZ interference.

UESA has no governance over the colonies and must respect their sovereign will for independence.

Long term, the reason to expand into space is to expand into space. The point of going to Mars is not to make money. The point is to find a way for people to live there.

Let go of your sci fi visions of the future. Space colonization does not look like humans getting on a rocket ship on Earth's surface, blasting off between stars, and landing on a second Eden around another star, a world where you can take your helmet off, breathe the local air, eat the food, and drink the water. What we've learned from our exoplanet studies is that the cosmos has exercised infinite creativity in generating new Hells, worlds uninhabitable and lethal to us in ways we never even dreamed of.

Real space colonization is going to take a whole lot of engineering and building. Mars is actually quite habitable compared to the vast majority of worlds in the universe. If you have some basic self-replicating machines, making Mars habitable is quite doable. Cover as much of the surface as you want in vast greenhouses. Live under domes potentially spanning the entire world. Long term, Mars has great potential for human settlement.

As for why? Well I would say it's a moral responsibility. We know if we stay on just one planet, just one star, then it's only a matter of time before some natural or artificial disaster wipes us out, and possibly the rest of life along with it. Earth has the type of biosphere you probably have to scour multiples galaxies to find one of comparable complexity. That's a jewel worth protecting.

We tend to be too hard on ourselves as as species, viewing ourselves as some sort of cancer on the world. At the same time, we are the only hope for life on this planet to survive past a certain point. We are the children of Gaia. It's our duty and moral obligation to spread life as far and wide as possible. Life itself has intrinsic value. And it's our job to spread it.

Right now we're all kinda eggs in one basket. Earth is one good cataclysm from wiping out humanity.

But we're not just going to sort out spreading to other planets without baby steps.

The ISS was the first step. We need a large enough permanent base to see whether agriculture and 100% recycling can work. They still need supplies from earth for now, but long term, can we make it work? how big does a settlement need to be?

cheaper access to space:

The moon is an interesting prospect. It's significantly further up the gravity well. We might be able to launch small probes via a rail gun, then use ion engines. No atmosphere to fight.

Radio Astronomy:

Anything not aimed at earth could be super sensitive.

Fuel:

we might be able to farm oxygen and hydrogen from water/minerals. and make a depo.

Deuterium might be worth mining, but ¹/₆ gravity will wreck you, just like the martian atmosphere without a magnetosphere. And martian dust is so fine it'll wreck everything as well.

Or we stop being a dipshit race and stop screwing the spaceship we live in.