NASA's Rover Opportunity has found another clay-rich rock on the Martian surface, which confirms that Mars was once a water-rich planet.

NASA launched Curiosity rover with the main intention of determining whether Mars ever was capable of sustaining life as we know it. NASA has come across evidence that suggests there is a huge possibility that the Martian surface did indeed support life once upon a time. Now, a new discovery has reconfirmed that fact. NASA's Rover Opportunity has found another clay-rich rock on the Martian surface, which confirms that Mars was once a water-rich planet.

The rock discovered is the size of a person's forearm and was found by Mars rover Opportunity, one of the older spacecrafts still in operation on the planet. Scientists have named the rock Esperance and confirm that it is one of the oldest rocks Opportunity has looked at during its nine and a half years on Mars. The rock was found to contain an abundance of elements like calcium magnesium and aluminium.

"This is powerful evidence that water interacted with this rock and changed its chemistry, changed its mineralogy in a dramatic way," said Steven W. Squyres, the principal investigator.

Though the word Esperance actually means "Hope," scientists reveal that the name was given to the rock after a gold mine in French Guiana where a project member had done research and found more neutral water.  "This is water you could drink," Dr. Squyres said. "This is water that was probably much more favorable in its chemistry, in its pH, in its level of acidity, for things like prebiotic chemistry, the kind of chemistry that could lead to the origin of life."

Opportunity is now headed for a 180-foot hill called Solander Point, less than a mile away, where there is a possibility of finding more clay-rich rocks.