NASA announced Wednesday that Curiosity has begun its longest drive yet to Glenelg, an intersecting geographical rock formation that lies east of the rover's landing site on Mars.

"This drive really begins our journey toward the first major driving destination, Glenelg, and it's nice to see some Martian soil on our wheels," said mission manager Arthur Amador, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a press release.

"The drive went beautifully, just as our rover planners designed it."

Although the drive to Glenelg will only be one stop on the rover's two-year mission, this and other discoveries so far have scientists excited.

"Certainly lots of hypotheses and speculation amongst the scientists in terms of what kind of environment was here where we landed," said Richard Léveillé, a Canadian scientist who was chosen to work on the Curiosity mission.

"What are the rocks around us? How did they form? What do they represent? What do they tell us about the past environments here in Gale Crater?"

Even though it's only three weeks into the mission, scientists like Léveillé are asking these questions and already getting some answers. Photos NASA released on Monday show Curiosity's Mount Sharp in the far distance.

The images were generated by one of Curiosity's Mastcams, which is equipped with a 100-millimetre telephoto lens.

"You can see layers of strata in this. Just like looking at the Rockies from a highway," said Jonathan Spray, a planetary scientist at the University of New Brunswick, who is also working on the mission.

A chapter of the layered geological history of Mars is laid bare in this postcard from NASA's Curiosity rover. The image shows the base of Mount Sharp, the rover's eventual science destination. (NASA / JPL-Caltech)

NASA suspects that in these layers of sand sits a motherlode of information about how Mars was formed and whether or not the red planet is capable of sustaining life.

NASA has already acquired data from its ChemCam, a camera that analyzes the chemical composition of rock. Running the instrument through a number of tests, Chemcam has generated some qualitative data about what kinds of rocks are sitting around Curiosity, but it hasn't been able to tell what percentage of the rock is composed of elements like iron and magnesium.

"Right now it has been saying that we can see this element, but we cannot exactly tell you how much is in there," said Léveillé.

The NASA Mars space team has also had a chance to test out the alpha particle X-ray spectrometer (APXS), a device that was developed at the University of Guelph and stands as Canada's contribution to the $2.6-billion Mars rover. It can determine the chemical composition of a rock or soil sample.

The instrument is located on the rover's arm, and even though Curiosity's arm hasn't been deployed, NASA scientists tested the APXS taking an air sample that detected trace amounts of argon in the atmosphere.

Léveillé is optimistic that when the ChemCam and the APXS are used in tandem, it will yield even more detailed results.

"They should be able to detect elements that aren't super abundant, but that are in lower abundances that may be considered minor elements or trace elements," Léveillé said.

En route to Mount Sharp

Once the tests are all complete, Curiosity's ultimate goal is to scale the five-kilometre-high Mount Sharp. But along the way, the rover will be heading to Glenelg, an area of intersecting rock that's about 400 metres away and has captured the attention of scientists.

NASA christened this rock formation Glenelg, which is "glen" spelled forwards and backwards, because they said Curiosity will bypass this area as it heads east along Gale Crater and then pass by it again as it heads back west and journeys to Mount Sharp.

"There's something interesting going on there, and it is a chance to look at different geological units in close proximity," Léveillé said.

NASA has determined through orbital satellites that Glenelg contains geological formations that may tell a different story about how Mars was formed.

One rock strata of particular interest is a light-toned region that appears as a bright area in thermal readings from orbiting satellites.

"That possibly means that it is hard rock cemented as oppose to loose, dusty soil," Léveillé said. "It doesn't look like volcanic rock; it looks like something else. We can't tell what. It's compelling enough to look at it closely."

Another member of NASA's Curiosity team, Albert Yen, who also works with the APXS, said that this area is especially important because it can provide a snapshot of Gale Crater.

"If you were to do a geological map of this area, you would say there are three different types of terrain all at this one point. So when you go there and examine the inter-relationships between the terrains, you will hopefully understand the evolution of the material in Gale," Yen said.