[andrewb]

I don't think the Ireland example is the best. My understanding is they left because their home country was poor and the grass looked greener in America (land of opportunity and all).

The grass does not look that green in Mars

[rowanseymour]

That is true but I was only comparing in terms of not seeing one's family again. It's hard to imagine saying good bye to your friends and family and knowing you won't likely ever see them again.

Most Irish left for America during the potato famine so didn't really have much choice in the matter - it was emigrate or starve.

[dwild]

It depends on your perception. For some people the land of Mars can be greener. The knowledge we would get back from that is huge and can be a huge opportunity. I agree that most people doesn't think about everything they will quit but I think we can find people that are ready to do it.