[Imerso]

You can do the same experiments inside the gravity well of Earth, without the extra cost of sending humans and all the survival equipment required.

With all the money that you save you can experiment with humans close to Earth and use the money you save to send many robots to do the actual exploration, which will survive longer than humans and do much more work.

Of course you won't get the same publicity. So maybe just for that it's better to send humans, but not for scientific reasons.

[bane]

> You can do the same experiments inside the gravity well of Earth, without the extra cost of sending humans and all the survival equipment required.

No you can't. You simply can't put people on Mars without putting people on Mars. All that extra equipment is the experiment. Operating for years at a time in Mars local environment is the experiment. Getting humans out of Earth's gravity well and living, generationally on some other ball of rock (or in a habitat of some kind) is the experiment. You can't ever do those things without actually doing those things and doing that is the experiment.

The single most important question that we have to answer is this, can we or our descendants survive the cataclysmic destruction of our planet by colonizing space, or are we an evolutionary dead-end, destined to be snuffed out the first time the sun burps in our direction or an island sized boulder plows into Europe? Are we no better than all the other helpless animals who evolution didn't gift with the power of survival in the face of absolute destruction, or is that gift real? Are we just fancy, clothes wearing, monkeys?

Answering that question is answerable with only one experiment, and that's actually doing it. It's an endeavor that makes the necessity of something like the LHC look like child's play, but the answer it yields could be the difference between our collective termination and the future survival of our progeny.

No amount of simulations or probes can ever answer that. That's a path towards the slow extinction of our species, surrounded by the knowledge of the cosmos, as gathered by our instruments, but not our senses.