Recently, NASA investigators announced that they have detected “non-thermal radiation” from the Martian surface. Since the energy readings were independent of the surface temperature, and occurred during one of the giant dust storms that sometimes rage through the southern plains, the assumption is that they are evidence for lightning discharges.
The link to that source shows that it is from a press release issued by the University of Michigan at Ann Arbor, MI,in June of 2009, regarding findings of observations measured by a microwave instrument on one of the two previous Mars Rovers.
The first direct evidence of lightning has been detected on Mars. Researchers from the University of Michigan found signs of electrical discharges during dust storms on the red planet using an innovative microwave detector . The bolts were dry lightning, said Professor Chris Ruf. “What we saw on Mars was a series of huge and sudden electrical discharges caused by a large dust storm. Clearly, there was no rain associated with the electrical discharges on Mars. However, the implied possibilities are exciting.
One shouldn't be too quick to agree that their interpretation - that the dust storm caused the lighting discharges - is correct, as it might have been the other way around, with twisting electromagnetic discharge conditions in Mars' this atmosphere picking up and ionizing surface and atmospheric particles to create the dust devils and sandstorm conditions that accomanied the discharges. Pictures of dust devils with bright, arc-light-looking tops have been posted on this Forum previously, those same dust devils that leave those beautifully stark, blackened trails criss-crossing and weaving erratic patterns in certain areas in the HiRise satellite photos.
While Mars does not have a strongly organized magnetic field and magnetosphere like many planets in our system, it still provides evidence of continuing small-scale electrical activity, and older, historic large-scale evidence of cosmically-scaled electrical discharges such as Calles Marinaris and Olympus Mons, and its smoothed northern hemisphere that is much lower than the rough terrain of the southern hemisphere. Without a significant atmosphere and no magnetosphere, it is subject to much more intense solar bombardment, both radiation and charged particles from the solar wind, than denser, magnetized planets with thick atmospheres elsewhere. It may be that the solar wind is a feeder circuit to Mars and possible the source of charge imbalances which occasion the lightning discharges.
I would suggest that electricity needs to become elevated to a more prominent position in the planetary geologists' bag of explanations for what they are seeing with the clear, fresh eyes of these clever robotic explorers.