Washington, Nov 22 (IANS): The Curiosity Mars rover has made a potentially explosive discovery, but NASA scientists are keeping it under wraps to double-check the spacecraft's calculations, RIA Novosti reported.

Chief mission scientist John Grotzinger told National Public Radio that the possible discovery, gleaned from a sample of Martian soil collected by the six-wheeled vehicle, will "be one for the history books". "It's looking really good," he said.

But Grotzinger, a geologist at the prestigious California Institute of Technology, added that NASA scientists are taking every precaution to verify the data collected by Curiosity, which was launched late last year and landed on Mars in August.

The news follows on the heels of what scientists earlier thought was the discovery of methane - typically a sign of living organisms - on Mars, Grotzinger said, only to determine later that the air likely accompanied the spacecraft from its Florida Launchpad.

He added that NASA would convene a press conference in early December to reveal the results of Curiosity's research.

Scientists, meanwhile, have let their imaginations run wild as to what Curiosity might beam back to earth.

"If it's going in the history books, organic material is what I expect," Peter Smith, a University of Arizona researcher who served on a 2008 Mars mission for the Phoenix Lander, told online tech website Wired.

"It may be just a hint, but even a hint would be exciting," he added.