Why Go to Mars? Scientific American

Today Mars looms as humanity’s next great terra incognita. And with dubious prospects for a short-term financial return, with the cold war a rapidly receding memory and amid a growing emphasis on international cooperation in large space ventures, it is clear that imperatives other than profits or nationalism will have to compel human beings to leave their tracks on the planet’s ruddy surface. Could it be that science, which has long been a bit player in exploration, is at last destined to take a leading role? The question naturally invites a couple of others: Are there experiments that only humans could do on Mars? Could those experiments provide insights profound enough to justify the expense of sending people across interplanetary space?