With what appears to be vast reserves of frozen water, Mars "is nearer terrestrial conditions, much better than the Moon and any other place," Aldrin, 78, said in a visit to Paris on Tuesday.
"It is easier to subsist, to provide the support needed for people there than on the Moon."
It took Aldrin, Neil Armstrong and Michael Collins eight days to go to the Moon -- 380,000 kilometres (238,000 miles) from Earth -- and return in July 1969, aboard Apollo 11.
Going to Mars, though, is a different prospect.
I hereby volunteer.