SchrodingerZ writes "Last week the Mars Curiosity Rover spotted a shiny metallic-looking object in the martian soil. This week scientists have confirmed that it is plastic that has fallen off the 1-ton rover. However, the discovery of this trans-planetary littering has opened up another mystery for the science team. On October 12th the rover took a sample of soil from the ground, feeding it into its Chemistry and Mineralogy (CheMin) instruments for analysis, and a picture of the hole dug by the rover's claw revealed metallic particles in the dirt. The sample was subsequently dropped due to fears that particles from the rover had made it into the dirt. Further study now suggests that the metallic particles are actually native to Mars, as the photo reveals that they are embedded in the soil in clumps. In 2007 the older rover Spirit found evidence of silica for the first time, more testing will occur over the next few days to determine truly if this is again just Curiosity's littler, or something more profound."