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 and then touch something metal.
Experiments have hinted that the red dust coating the surface of Mars could be electrified like this, but for the most part those experiments have included other factors that could have contributed to the accumulation of electric charge. For instance, if dust particles touch the walls of the experiment鈥檚 containers, they could build up charge.
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Joshua M茅ndez Harper at the University of Oregon and his colleagues devised an experiment that is as close to Mars-like conditions as possible, with the dust particles touching only each other and not any human-made surface. To do this, they used bursts of carbon dioxide in a low-pressure chamber to create a fountain of artificial Mars dust before measuring the electrical effects of the particles rubbing together.
They measured charges of about the same strength that you can typically get from rubbing two materials together to create static electricity. The sparks produced weren鈥檛 visible, but the researchers were able to detect them with an antenna.
This build-up of electric charge could be an issue for human exploration of Mars.
鈥淲e are eventually going to send humans to Mars, and all this static electricity will be pretty hard to deal with for a human mission,鈥� says Alian Wang at Washington University in Missouri. The Apollo astronauts had moon dust collect in the creases of their suits, and the same could happen to explorers on the Red Planet. The small electric shocks from the dust could be a problem for the electronics embedded in the suits, she says.
This could also be important to our understanding of Mars because the electric charges could cause chemical reactions in the dust there. In experiments using chlorine, which is all over Mars鈥檚 surface, Wang and her colleagues have found that small electric discharges like the ones demonstrated in M茅ndez Harper鈥檚 experiments could be key to the reactions that release chlorine from other compounds and distribute it around the surface and atmosphere.
They have also found that those same reactions generate highly reactive particles that could drastically affect the surface chemistry of the Red Planet, including destroying the chemicals that are considered signs of possible life.
鈥淚f each storm and each dust devil induce lots of chemical reactions, then searching for signs of life would be very hard,鈥� says Wang. 鈥淲e could go to Mars to look for those signs and not find any on the surface or the subsurface because it got essentially cleaned up by these electrical discharges.鈥�
In other words, Mars鈥檚 electric dust could make it impossible for us to find signs of past life on the surface.
References: ; Journal of Geophysical Research: Planets,
