NASA/JPL-Caltech/MSSS
Sparks may be flying on Mars. The grains of dust there can rub together and become electrically charged, which could cause chemical reactions that would make it difficult to spot signs of life on the surface.
When grains of dust or sand rub together, they can build up an electric charge the same way that shuffling your feet on the carpet can build up static electricity. Those grains can then release the charge in sparks similar to those that shock your fingertips when you have built up enough static electricity …
source: newscientist.com