[alex_duf]

>I never understood why colonizing Mars is needed.

Personally I see quite a few positive things behind colonising Mars.

I think it's not about having a "backup", it's not about resources (or in a really long time) it's about the challenge.

If we can put our best engineers to solve how we re-use and recycle water, how we grow crops in extreme condition, how to control the O2 CO2 cycle (at a larger scale than on the space station), how to engineer a space craft that survive such harsh conditions we will end up with:

- technology to help our crops on earth

- technology to help with our water crisis

- technology to build sturdier structures

- international collaboration, that usually keep engineers from working on mass weaponry (The USA/Russian space program is actually motivated by exactly that: keeping the rocket scientists busy instead of working on ICBMs)

Mars just happen to be a goal silly enough that we'll get interesting discoveries and advances that I can't even foresee.

Another way to keep engineers busy and force international collaboration is to have a common threat. For that I believe the asteroid threat is both a real enough threat and a good subject to work collaboratively.

[da_chicken]

It's kind of like learning how to program when you don't have any task to complete. Especially for a data store of some kind. If you've ever tried to learn SQL, even if you've got an example database, you'll find it's incredibly difficult not because the syntax is all that difficult or the logic is particularly daunting. No, you'll find it's difficult because you don't have any questions to answer. You'll feel, "Okay, now what?" When you try to make up a question to answer, it's difficult to tell if you're answering the question correctly. You need the focus that a real problem gives you. You need the guidance that understanding what the data means gives you (or someone else) to know if your answer is right or wrong.

It's easy to see what a tool is designed to do. It's very difficult to see what a tool can be used for and why you might want to use it that way, let alone when you might want to deviate from that or find alternatives due to limitations or new requirements. Or when you might need entirely different tools.

We learn best when we're working on a problem. Just like going to the moon required solving a lot of problems which led to major advancements in the 20th century, going to Mars, colonizing Mars, and colonizing the moon have even more challenges.

Goals give research and development a clear purpose beyond, "I dunno, make something people want that we can sell."

[squish78]

I'm saving this answer. Love it.

[mr_overalls]

Not to mention that Mars gives humanity an opportunity to improve skills essential to expanding to other solar systems.

Besides the obvious - large-scale terraforming - a "practice" settlement of Mars gives us an opportunity to innovate and refine practically every engineering skill, form of social organization, or general skillful endeavor in humanity's repertoire.

Metallurgy, genetics, geology, farming, medicine, psychology - all of these fields are bound to discover new phenomenon and methodologies under the constraints and conditions of an alien planet.

Not to be glib, but necessity is mother of invention. And there is no necessity as powerful as the drive for survival.

[WorldMaker]

There's an old sci-fi idea, that if I recall Carl Sagan agreed with, that we should be working to colonize Venus now (which I believe "now" meant the 1970s at the time), because worst case if the greenhouse effect spirals out of control unstoppably (as climate change predictions have feared since the 1970s), surviving on Earth is going to be the same problem as colonizing Venus.