NASA says a small meteorite, possibly the first discovered from the martian surface, contains 10 times more water than meteorites that later originated on Mars.

Scientists have spent a year studying the meteorite dubbed Northwest Africa 7034 found in 2011 in the Sahara Desert and have determined it formed 2.1 billion years ago during the beginning of the most recent geologic period on Mars, known as the Amazonian, the space agency reported Thursday.

"The age of NWA 7034 is important because it is significantly older than most other martian meteorites," Mitch Schulte of the Mars Exploration Program at NASA Headquarters in Washington said. "We now have insight into a piece of Mars' history at a critical time in its evolution."

Although similar to surface rocks and outcrops NASA has studied remotely via Mars rovers and Mars-orbiting satellites, NWA 7034's composition is different from any previously studied Martian meteorite, researchers said.

"The contents of this meteorite may challenge many long held notions about martian geology," John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, said.

NWA 7034 is made of basalt, rock that forms when lava quickly cools, and researchers theorize the large amount of water may have originated from interaction of the cooling lava with water present in Mars' crust.

"This unique meteorite tells us what volcanism was like on Mars 2 billion years ago," said Carl Agee, leader of the analysis team and director of the University of New Mexico's Institute of Meteoritics in Albuquerque. "It also gives us a glimpse of ancient surface and environmental conditions on Mars that no other meteorite has ever offered."