Mars rover shows planet could have supported life

Mars in the past had some of the right ingredients needed to support primitive life, scientists said on Tuesday.

The latest evidence comes from a chemical analysis by the rover Curiosity, which last month flexed its robotic arm to drill into a fine-grained, veiny rock and test the powder.

The rover got lucky with that first rock, scientists said.

"We have found a habitable environment that is so benign and supportive of life that probably if this water was around and you had been on the planet, you would have been able to drink it," said chief scientist John Grotzinger of the California Institute of Technology.

Curiosity is the first spacecraft sent to Mars that could collect a sample from deep inside a rock.

The rover made a dramatic landing in August near the planet's equator, with the task of discovering whether ancient Mars ever had conditions favorable for microscopic organisms.

Clues to this habitable environment come from data returned by the rover's sample analysis at Mars, and chemistry and mineralogy instruments.

The data indicate the Yellowknife Bay area the rover is exploring was the end of an ancient river system or an intermittently wet lake bed that could have provided chemical energy and other favorable conditions for microbes.

The rock is made up of a fine grain mudstone containing clay minerals, sulfate minerals and other chemicals. This ancient wet environment, unlike some others on Mars, was not harshly oxidizing, acidic or extremely salty.

Scientists plan to work with Curiosity in the Yellowknife Bay area for many more weeks before beginning a long drive to Gale Crater's central mound, Mount Sharp. Investigating the stack of layers exposed on Mount Sharp, where clay minerals and sulfate minerals have been identified from orbit, may add information about the duration and diversity of habitable conditions.

Curiosity, loaded with the most-sophisticated instruments ever used to explore another world, will use its 10 instruments to investigate whether conditions have been favorable for microbial life and for preserving clues in the rocks about possible past life.

The car-size rover is not equipped to detect microbes, living or extinct. It can only use its onboard laboratories to examine Martian rocks to determine the kind of environment they might have lived in.

AP-Xinhua

(China Daily 03/14/2013 page12)