Colonizing other planets is not a good plan

Observing and exploring the Galaxy definitely have a lot of benefit to science. I don't like Capitalism much but is it worth burning that size of budget or money that comes from somewhere ..? The point should be things have to be analyzed and measured, and what we would have in return.

That's also not what colonizing is about. Rocket energy costs mean we'll never, ever lift more than at most a few thousand people out of earth gravity. Never. Not even with reusable rockets. 99.99% of the human population, at minimum, can never leave the earth.

> The challenges and adventure of not having water, facing problems like living on Venus clouds, etc.. are exactly the main reasons to go there. Doing what no other person has done ever has lots of advantages for the individuals doing it and human society as a hole.

The whole point of colonization is never coming back. It won't be about science for at least a couple generations. It'll be about babies, food and building extremely basic structures.

Those babies, incidentally, will be thoroughly fucked compared with babies on earth : They'll be locked in a small structure that they can never leave. And of course the project is dependent on them having at least 5-6 babies per couple, preferably more. They can never go to earth, ever. Hell, they can't ever so much as talk to anyone outside of their society that will be tens of people for a generation (because of the delay).

> For example when the first vehicles were sent to the moon we were able to discover that most rocks or sand were not affected by erosion or air pressure so they had properties not seen on Earth.

We knew those properties long before humans ever set foot on the moon.

We have plenty of ways that a small group of humans could be isolated and fed for the time it would take to make humans survive. Humans would not go extinct due to an asteroid impact, rest assured.

There's even a few places that would have natural protection from most of the phenomena. And of course, there'd be a few weeks where, starting 500km from the impact site or so, there would be essentially nothing wrong on other than a stripe in the sky. That time can be used to prepare for what's coming, and as long as you only try to save 0.1% of the population, you could do that just fine.

And there's plenty of calamities that would affect mars just as much as they'd affect earth. A supernova within 50 lightyears or so of earth (depending on size can be a bit more) is not survivable. That would destroy the atmosphere in a matter of seconds and kill the power grid, and there would be no warning at all (it's like an earthquake, we would "know it's coming" give or take 100000 years or so, and yes, there's one "ready to blow" within that range). Within 20 light years or so and we'd see wind speeds on the surface would go absolutely insane within a few minutes, lasting a few hours (there'd be a VERY hot wind with speeds that'll probably exceed the speed of sound for a few minutes). Anything above the surface is gone. Hell, this will erode the himalayas by several hundred meters at least, maybe kilometers. Ocean water levels will drop dozens of meters and there'll be zero water left on land.

But, on earth, some installations would probably survive even this. It won't be pleasant, because life on earth will take decades to centuries to come back to the point that the planet is covered in green (depending on what it does to the soil, might even be hundreds of thousands of years).

For all these calamities, the same thing keeps coming back. What you need is

a) a huge, huge mass surrounding you (the earth counts as "surrounding" us since there's always 50% of the surface that's protected by the mass of the earth), preferably with lots of metal inside of it.

b) an energy source that isn't dependent on anything (which means: a nuclear reactor). Obviously solar panels won't do.

c) a way to grow food and scrub co2 directly using just energy.

d) we'll need to do this using extremely well established technology. For instance, we can probably use computers from, say, a 50nm process, but we can't really go higher than that as we wouldn't be able to replace them. Because these events would wipe industry from the earth that means we can only depend on technology that can be made within whatever base we use.

That will let us have large amounts of survivors on our planet. The biggest problem seems to me to be C. We can do it, sort of, but not very efficiently.

Also, once we leave earth, we shouldn't go to Mars. Once we escape Earth's gravity we'd be wise never to dive into a gravity well again. We should migrate populations into asteroids and use them with ion engines as spaceships. With the people living deep into the interior. They will be far, far safer than Mars or any planet.

I think in practice we will colonise mas but no more than we are colonising Antarctica. The ITS will make going to a Mars affordable and there are good scientific reasons for wanting to do so. But my most optimistic scenario is that we'll have small bases on Mars for at least a generation testing out technology before well even begin to be able to dream about making such a station in any way self sustaining, even just in food, air and water let alone anything more complex.