NASA's Curiosity rover has uncovered a "bright object" in the red soil of Mars that might be a part of the robotic explorer that broke off, the US space agency said.

"The rover team decided to refrain from using the rover's robotic arm on Oct. 8 due to the detection of a bright object on the ground that might be a piece from the rover," NASA said Monday in a statement.

"Curiosity is acquiring additional imaging of the object to aid the team in identifying the object and assessing possible impact, if any, to sampling activities."

The rover had parked at a sand pit late last week, where it was to scoop up soil in order to clean and test its geological sampling hardware.

Curiosity is on a two-year mission to explore the Red Planet and learn whether conditions there might have been able to support life in the past.

The $2.5 billion craft landed in Gale Crater on August 6, opening a new chapter in the history of interplanetary exploration.