Probes like Spirit must find the 'right stuff,' like water
Humans on their tiny planet have found a stellar way to usher in a new year, if not a new era.
In recent days, they've successfully probed the planet Mars, a comet, and the galaxies in separate attempts to discover the essential ingredients for organic life beyond Earth.
Like the earliest ocean explorations of centuries past, these latest technological advances relied on lessons learned from earlier mistakes - especially in reaching Mars. They reaffirm a human desire to know how chemical life began, and whether it can have - or ever had - multiple origins in the universe.
The most spectacular venture was Saturday's landing of the first of two robot-geologists on Mars. The mobile lander Spirit quickly sent back pictures of the Gusev Crater, which is thought by some scientists to be a dry and ancient lake bed with a channel system often associated with liquid water.
Spirit's twin rover, Opportunity, is due to land on Jan. 24 halfway around the planet on another site that has the potential for water. It will search for a type of iron oxide mineral most often found in iron-rich water.
Both golf-cart-sized water seekers are the most sophisticated scientific probes ever sent to another planet. They build on the limited successes of the 1976 Viking landing on Mars and the 1997 explorations by the tiny Sojourner robot, and will bring a whole new sophistication to the geological understanding of the planet.
They are expected to explore more than two miles of Mars - snapping photos, grinding surfaces, and analyzing minerals - for at least three months, with the primary aim of looking for hints of past water, or even reservoirs of ice below the surface, that could suggest Mars was warm and wet billions of years ago.
The NASA probes represent a quickening pace among space-exploring nations to find out if Mars was ever once habitable by some sort of life. Unfortunately, probes sent by Japan and Europe failed in recent weeks, but NASA's success with Spirit and perhaps Opportunity gives hope that more landers will be sent every 26 months, the interval of time for Earth and the Red Planet to draw closest in their orbits.