Nasa has unveiled plans for its Mars rover Curiosity's first road trip, part of a two-year quest to determine if the planet most like Earth could ever have hosted microbial life, scientists said.

The one-ton nuclear-powered robotic science lab landed in a large crater near Mars' equator on August 6 to search for organic materials and other chemistry considered key to life.

The rover's primary target is Mount Sharp, a mound of layered rock 5 kilometres high rising from the floor of Gale Crater. 

Before beginning the 7km trek to the base of Mount Sharp, a journey expected to take months, the six-wheeled Curiosity will visit a relatively nearby site named "Glenelg" which caught scientists' interest because it includes three types of terrain. 

The name was selected from a list of about 100 rock formations in northern Canada. Scientists realised Glenelg was a palindrome - a word that reads the same backward - and particularly suited as the name for Curiosity's first destination since the rover will have to come back through the site to head to Mount Sharp.

The road trip to Glenelg depends in part on how well Curiosity cruises through the rest of its instrument checkout. Early next week, the rover will test-fire its powerful laser to pulverize a bit of bedrock uncovered by exhaust from Curiosity's descent engine. 

A small telescope will then analyse the vaporised material to determine what minerals it contains. 

The combined system, known as Chemistry & Camera, or ChemCam, is designed to make about 14,000 measurements throughout Curiosity's mission, said lead instrument scientist Roger Wiens, with the Los Alamos National Laboratory. 

"There's a high-power laser that briefly projects several megawatts onto a pinhead-size spot on the surface of Mars," Wiens said. "It creates a plasma, or a little ball of flame or spark." 

The telescope, which can observe the flash from up to about 8 metres away, then splits the light into its component wavelengths. 

Scientists use that information to determine chemical composition. 

Travel to Glenelg, located about 550m away from Curiosity's landing site, should take a month or longer, depending on how many stops scientists decide to make along the way. 

"Probably we'll do a month worth of science there, maybe a little bit more," lead mission scientist John Grotzinger told reporters during a conference call on Friday. "Sometime toward the end of the calendar year, roughly, I would guess then we would turn our sights toward the trek to Mount Sharp."

- Reuters