From his new home on the Red Planet, NASA’s Perseverance may soon have a preview of another world light show.
When the next seasonal dust storm passes through the Jezero crater (where the rover landed on February 18), the air around the rover may crackle with purple light and glow from the collision of statically charged dust particles, a new study indicates.
These colorful sparks would almost certainly be too small and weak to pose a threat to endurance or to hypothetical people walking March in the future, said lead study author Joshua Méndez Harper, a geologist from the University of Oregon. However, the presence of electrostatic forces on Mars could have major implications for the way scientists understand the atmosphere of the Red Planet and its potential to advance life, Méndez Harper said.
Related: Here’s the last thing NASA’s Opportunity Rover saw before it ‘burned’
‘Small sparks can catalyze the production of chemicals [impact] the presence of organic materials, “Méndez Harper said in an email to WordsSideKick.” A recent article suggests that perchlorate – compounds that are toxic to many life forms – can be generated by small-scale discharge. “
The buzz about Mars
The new study appears in the March issue of the journal Ikarus, aims to answer decisively a question that has been buzzing through the scientific community for half a century: Can colliding particles whipped up by high-speed winds in Mars’ atmosphere spark electricity?
This process is known as triboelectric charging – that is, electricity produced by the friction of colliding particles or surfaces. On Earth, you may generate a small triboelectric spark, or Static Electricity, in your bedroom by rubbing your socks on the carpet and then touching a metal doorknob (itching!). Or, for a larger demonstration, you may marvel at a apocalyptic lightning storm by bolting the ash column of an erupting volcano – the triboelectric consequence of ash particles colliding in the air.
On Mars, however, it is unclear whether triboelectric charging occurs at all. Because Mars has much lower atmospheric pressure than Earth, it is unlikely that powerful charges can build up there, Méndez Harper said. Studies dating back to the 1970s have attempted to simulate dust storms on Earth by shaking up volcanic ash in small low-pressure containers. Sometimes the particles (which are similar in composition to Martian dust) sparkle, but according to the new Icarus article, these studies can be fundamentally flawed.
“These works did not take into account the possibility of loading arising from the interaction between simulated Martian dust and experimental containers enclosing it,” said Méndez Harper. “The containers often had different chemicals – plastic, metal or glass – that could cause the observed electrical effects.”
In other words, in previous studies, any sparks observed may actually be between a dust particle and the side of the container enclosing it, rather than between two simulated Mars dust particles. These containers are made of things that do not exist on Mars, which means that the experiments actually teach us nothing about what is happening inside the dust storms of the Red Planet.
Méndez Harper and his colleagues tried to correct this experimental design flaw in their new study.
Similar to previous experiments, the team used volcanic ash grains (from the Xitle volcano in Mexico, which erupted about 1700 years ago), to simulate Mars dust particles, and locked them in a glass tube under conditions that alter the atmosphere of the Mars simulates. Unlike previous experiments, however, the team has radiators of carbon dioxide to stir the granules into a “fountain” of colliding particles that never touches the container wall.
The team found that the colliding particles did result in small triboelectric sparks, even when the dust grains did not come into contact with the container. For the researchers, this study then provides the first reliable experimental evidence of triboelectric charging on Mars.
Red planet, purple glow
What would those charges look like? That’s hard to say. Although the researchers detected electronic shocks in their Mars dust fountain, they did not observe any visual effects as a result of the collisions. Given the low atmospheric pressure on Mars, it is unlikely that even the fiercest dust storms will ripple with lightning such as terrestrial volcanoes or thunderclouds.
“A more likely possibility is that Mars’ dust storms will display innumerable small sparks – called spreader discharges and glow discharge,” Méndez Harper said. These small-scale electrical effects can make Mars’ purple clouds glow; on earth, sailors sometimes see a similar glow – known as St. Elmo’s fire – as the masts of ships scrape through a strong electric field.
The Perseverance Rover could possibly get the first visual evidence of the phenomenon on Mars the next time a dust storm washes through the Jezero crater – or possibly even earlier, Méndez Harper said.
“Percy” is equipped with a small helicopter called Ingenuity; Méndez Harper, when the cop takes off or lands, his wringing blades can stir up enough dust to effect ‘visible discharge’.
Do not be shocked when you see it.
Originally published on Live Science.