(Sen) - Rovers on Mars have been analysing rocks to gain a clearer picture of the planet's past environment and to understand if it once had conditions suitable for life.
NASA's Curiosity rover has collected a powdered sample from a rock it drilled on May 19. This is the second rock drilled by the rover.
The rover drilled a hole about 1.6 cm in diameter and 6.6 cm deep in the target rock which has been named "Cumberland". The powder collected will be analysed by the rover's onboard tools in the coming days.
The rock is only about 2.75 metres away from the first rock drilled by Curiosity back in February, named John Klein. Both rocks are in an area named Yellowknife Bay.
Cumberland was chosen as the target rock for the second outing of the drill because it appears similiar to the John Klein rock and the sample collected will be used to verify findings from John Klein. The analysis of John Klein's powder by the rover's onboard laboratory was that in the ancient past there were environmental conditions favourable to microbial life.
Data returned from the John Klein rock indicated that Yellowknife Bay was probably the end of a river system in the ancient past.
After further exploration of the Yellowknife Bay area, Curiosity will begin a month long trek to the base of Aeolis Mons - also known as Mount Sharp - in the middle of Gale Crater.
Whilst Curiosity is the largest and most advanced rover ever built, its smaller hardy cousin, the Mars Exploration Rover Opportunity, has also been studying a rock for clues to the planet's past environment.
The pale rock in the upper center of this image called "Esperance" was inspected by NASA's Mars Exploration Rover Opportunity. Preliminary interpretation points to clay mineral content due to intensive alteration by water. Image Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ.
Opportunity has been at the rim of Endeavour Crater - which has a diameter of 22 kilometres (14 miles) - in an area called Cape York studying a rock dubbed "Esperance".
Although not armed with a drill or the ability to examine samples aboard its own laboratory, Opportunity does have an alpha particle X-ray spectrometer, (APXS) a camera and an abrasion tool. The rover exposed a patch of the rock's interior with the abrasion tool and used the camera and spectrometer to gather data. The rover found evidence the rock was once covered in water.
Scott McLennan, of the State University of New York and a member of the Opportunity science team, said: "What's so special about Esperance is that there was enough water not only for reactions that produced clay minerals, but also enough to flush out ions set loose by those reactions, so that Opportunity can clearly see the alteration."
Steve Squyres, the mission's Principal Investigator, observed: "Water that moved through fractures during this rock's history would have provided more favourable conditions for biology than any other wet environment recorded in rocks Opportunity has seen."
The team found the rock's composition had higher amounts of aluminium and silica, and lower amounts of calcium and iron, compared to previous rocks studied by the rover.
Opportunity is now making its way around the rim of Endeavour Crater to Solander Point, about 2.2 km (1.4 miles) from its current location.
Opportunity is one of two Mars Exploration Rovers that landed in 2004. Its twin, Spirit, ceased working in 2010. Opportunity has outlived its life expectancy by a considerable margin, having been built for just a 3 month primary mission.
Opportunity is managed by NASA's Jet Propulsion Laboratory (JPL) based in Pasadena, California. JPL also manages Curiosity - formally known as Mars Science Laboratory - which landed on Mars on August 6 2012 (UTC) on a two year mission to study the planet for evidence of whether the planet ever had conditions suitable for life.