During its two-year exploration, the plutonium-powered Curiosity will climb the lower mountain flanks to probe the deposits. As sophisticated as the rover is, it cannot search for life. Instead, it carries a toolbox including a power drill, rock-zapping laser and mobile chemistry lab to sniff for organic compounds, considered the chemical building blocks of life. It also has cameras to take panoramic photos.
Humans have been mesmerized by the fourth rock from the sun since the 19th century when American astronomer Percival Lowell, peering through a telescope, theorized that intelligent beings carved what looked like irrigation canals. Scientists now think that if life existed on Mars — a big if — it would be in the form of microbes.
Curiosity will explore whether the crater ever had the right environment for microorganisms to take hold.
Even before landing, it got busy taking radiation readings in space during its 352-million-mile cruise — information that should help its handlers back home determine the radiation risk to astronauts who eventually travel to the red planet.
Curiosity's journey has been fraught with bumps. Since NASA had never built such a complicated machine before, work took longer than expected and costs soared. Curiosity was supposed to launch in 2009 and land in 2010, but the mission — already $1 billion over budget — was pushed back two years.
The delay created a cascade. Burdened with budget woes, NASA reneged on a partnership with the European Space Agency to land a drill-toting spacecraft in 2018. The space agency is in the midst of revamping its Mars exploration program that will hinge heavily on whether Curiosity succeeds.
The extra time allowed engineers to test and re-test the rover and all its parts, taking a spacecraft stunt double to the Mojave Desert as if it were Mars. For the past several months, engineers held dress rehearsals at the sprawling JPL campus 10 miles northeast of downtown Los Angeles in anticipation of landing day when they will carry on a decades-old tradition of passing out "good luck" peanuts.
Practice is over. It's show time. To Mars or bust.
Follow Alicia Chang's Mars coverage at: http://www.twitter.com/SciWriAlicia
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