It turns out that men really may be from Mars, but so are women.
The idea, in numerous variations, is that about 4 billion years ago asteroids hit Mars, which then had a more hospitable climate than its current carpet of red dust. Meteorites colliding with Mars sent chunks of matter flying into space, some of which landed on earth.
Some of the meteorites may have transported key minerals from the Red Planet to Earth, theorizes Steven Benner, a professor at the Westheimer Institute of Science and Technology in Gainesville, Fla. Benner's theory -- presented last week at the international Goldschmidt conference and covered by the BBC -- suggests how ribonucleic acid (RNA), a compound with ingredients vital to living organisms, might have come to Earth, where certain minerals and proteins essential to life were scarce or nonexistent.
Somehow this stew of interplanetary ingredients evolved into living organisms, and these organisms evolved into humans. Mars was not quite so lucky. Insufficiently dense to hold onto an atmosphere, the Red Planet became a dead planet.
But mankind, now that it has the capacity for interplanetary travel, is driven to go to Mars. Even now, two U.S. rovers are trundling around its surface, digging, poking and prodding. High overhead, an American satellite is making a detailed map of Mars' surface. Can a GPS for Mars be far behind? But the space conversation keeps returning to putting astronauts, perhaps even a colony, on Mars. There are sound scientific reasons for this, but there is something deeper, less amenable to easy explanation.
Perhaps, at some primal level, we simply want to revisit the old neighborhood.