Curiosity Steps Up Search for Alien Life on Mars

NASA's Mars Science Laboratory ratchets up the quest to the next ingredient in the recipe for life -- organic carbon.

Radford Uchihara has applied to be among the first humans to set foot on Mars as part of the Mars One program.
DCI

THE GIST

- Mars rover Curiosity will look for environments where life could have taken hold -- and been preserved.

- The wheeled robot will explore a three-mile high mound of what appears to be layers of sediment.

- Touchdown is slated for 1:31 a.m. EDT on Monday.

With the arrival of NASA's Mars Science Lab on Monday, a new chapter begins in the age-old quest to determine if there is life beyond Earth.

The rover, nicknamed Curiosity, is not a life-detection mission per se. NASA tried that direct approach in the 1970s with the twin Viking landers. Considering what scientists later learned about the Martian environment, it was no surprise those experiments didn't lead to a rush of follow-on missions.

NEWS: Mars Viking Robots 'Found Life'

The quest of life on Mars bloomed anew in the 1990s in the wake of a stunning report that a Martian meteorite recovered on Earth had what appeared to be fossilized Martian bacteria. Later analysis refuted that conclusion, but it stimulated new ideas about how and where Martian life might have evolved.

Meanwhile, scientists were making new discoveries of life in extreme environments on Earth, opening up a range of potential habitats for life beyond the planet as well.

"At least in the past, Mars looks like it could have supported life," said NASA's lead Mars Program scientist Michael Meyer.

NASA's revamped quest for Martian life began with a simple premise: Find signs of past water, since water is believed to be a key ingredient for life.

Wide Angle: Rover Curiosity Ready for Mars Landing

Over the past decade, an increasingly more sophisticated armada of robotic probes returned strong evidence that Earth's little sibling dramatically changed at some point in its past, transitioning from a warm, wet world to the cold, dry and acidic desert that exists today.

Curiosity ratchets up the quest to the next ingredient in the recipe for life -- organic carbon, which provides structure for living entities. The key to finding it on Mars, if it exists, is to find places where it could have been preserved, a challenging proposition since the same processes that make rock tend to destroy carbon.