For centuries, explorers have ridked their lives venturing into the unknown for reasons that were to varying degress economic and nationalistic. Columbus went west to look for better trade routes to the Orient and to promote the greater glory of Spain. Lewis and Clark journeyed into the American wilderness to find out what the US. Had acpuired when it purchased Louisiana, and the A pollp astronauts rocketed to the moon ina dramatic show of technological muscle during the cold war .
Although their missions blended commercial and political-military imperatives, the wxplorers involved all acccomplished some significant sciencesimplu bu going where no scientists had gone before.
Today Mars looms as humanitu’s next great terra incognita.And with doubtful prospects for a short-term financial return, with the cold war a rapidly fading menory 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 reddish surface.Could it be that science, which has long played a minor role in exploration, is at last destined to take a leading role ?The question naturally invites a couple of others:Are ther wxperiments thet onlu humans could do on Mars?Vould thode experiments provide insights profound enough to justify the expense of sending pople across interplanetary space?
With Mars the scientific stakes are arguably higher than they have ever been. The issue of whether life ever existed on the planet, and whether it persists to this day ,has been highlighted by mounting evidence that the Red Planet once had abundant stable,liquid water and by the continuing controversy over suggestions that bacterial fossils rode to Earth on a meteorite from Mars.A more conclusive answer about life on Mars,past or present, would give researchers invaluable data about the range of conditions under which a planet can generate the complex chemistry that leads to life.If it could be established tht life arose independetly onMars and Earth,the finding would provide the first concrete clues in one off the deepest mysteries in all of science:the prevalence of life in the universe.