I've seen a couple posts about colonizing another body inside this system being "pointless" and that we really need to focus on going to other star
systems. I'm going to explain there are some very good reasons for colonizing here first.
Outside of science fiction, there's really only one natural disaster that can actually cause the extinction of our race, and that's a very large comet
or asteroid impact. Even supervolcano eruptions, while killing a high portion of our population, would probably not render us extinct because humans
are so adaptable. Gamma-ray bursts are another possibility but moving to another planet in our system probably wouldn't help with that. As for
asteroids/comets, the odds of one big enough to actually kill off our species are very low, but on a risk-reward scale, it's still worth planning
against. While we do have the technology to deflect asteroids now, we can only deflect the ones that are relatively small and would only cause
localized damage and moderate climate effects. The big kahunas are beyond our technology to move unless we had many decades or centuries to do it.
The point here is that, since it's possible (and over long time scales it becomes PROBABLE) we could be hit by something that kills every human on the
planet, for long-term species survival, it's imperative that we get some of our people living on another body as soon as we can. We aren't anywhere
even remotely in the realm of having practical interstellar travel, so just skipping interplanetary colonization until we have interstellar technology
would be extremely dangerous, for this reason. Such a large impact can happen next year or a million years from now, we simply don't know because
while we track and catalog a lot, we simply can't spot everything. Long-period comets are especially dangerous because they can remain beyond our
ability to spot until they're only a year or two away from hitting us. It's all a probability game, but with a truly disastrous consequence. So that's
the near-term case for colonizing inside our system ASAP.
The other reason colonizing another planet in our system will be necessary from a practical point of view is that our planet WILL continue to get
hotter, not because of anything we've done but because the sun will increase it's energy output as it ages. Consequently, Earth will eventually become
too hot for us to inhabit, so eventually we'll have to move the entire species off the planet. As our planet gets too hot to inhabit, bodies further
out like Mars will get hotter so that will actually be beneficial.
EVENTUALLY, billions of years from now we would have to move to another star system, but in the looooooooong interim before that becomes necessary,
it's anything but pointless for us to work towards being able to colonize inside our system.
One more thing, the shuttle has been mentioned, and I'd like to point out that the shuttle wasn't canceled because of a few accidents. They were
already moving to end the program before the Columbia disaster. It was canceled because it really didn't do what it was designed to do, which was to
make launching stuff into orbit more affordable. They designed it to be reusable hoping it would cut costs, but it cost so damn much to maintain them
that it didn't work out.
edit on 20-11-2016 by face23785 because: Sorry that was so long-winded, I never learned Brevity.