NASA's Mars rover Curiosity may have to find an alternative route to the base of a huge Red Planet mountain after the one-tonne robot got stuck in sand in the "Hidden Valley".
Curiosity had been heading for Mount Sharp - a 5.5 kilometres mountain in the centre of the Red Planet's Gale Crater - via "Hidden Valley," a sandy swale that's about the length of a football field.
However, according to NASA officials, the rover turned back shortly after entering the valley's northeastern end, finding the sand surprisingly slippery, 'Space.Com' reported.
"We need to gain a better understanding of the interaction between the wheels and Martian sand ripples, and Hidden Valley is not a good location for experimenting," Curiosity project manager Jim Erickson, of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said.
NASA officials said that there is no way out of the valley except the exits at its northeastern and southwestern ends.
The mission team is now exploring possible alternative routes that would take Curiosity north of the valley.
The goal is to get Curiosity to Mount Sharp, which has been the rover's ultimate science destination since before its touchdown in August 2012.
Scientists want the six-wheeled robot to climb up through the mountain's foothills, reading a history in the rocks of Mars' transition from a warm and wet planet in the ancient past to the cold, dry world we know today.
The chief goal of the USD 2.5 billion Curiosity mission is to determine if the Red Planet could ever have supported microbial life, the report said.
