I hope the Wikipedia editors have checked the info. In any case - I learned something. Yesterday I would have laughed at the idea of a colony on Mars as being total nonsense. And I'm annoyed at myself that like many non-scientists - I tend to forget simple science.

I assumed Mercury gravity was far lower because it's so much smaller. I entirely forgot about density.

Because Mercury is very dense, its surface gravity is 0.38g like Mars, even though it is a smaller planet.