Small Plastic on Mars to be determined

The ChemCam on the Curiosity Rover on Mars, picked up this very small object, appearing to be plastic, on the Martian soil…. And:

The rover team's assessment is that the bright object is something from the rover, not Martian material. It appears to be a shred of plastic material, likely benign, but it has not been definitively identified….

…A sample of sand and dust scooped up on Sol 61 remains in the scoop. Plans to transfer it from the scoop into other chambers of the sample-processing device were postponed as a precaution during planning for Sol 62 after the small, bright object was detected in an image from the Mast Camera (Mastcam).

Precaution against what? Hmmmmm…..
It could very well be something from the rover, but consider the alternative: If Mars was ever visited by alien races, their traces would be right there, preserved in the untouched Martian terrain. Now all we need to do is get up there and see for ourselves.

Nasa Story