For the first time, scientists caught a key engine of continuous erosion of the atmosphere of March in action.
It took more than nine years of data by satellite, but a team led by the planetary scientist Shannon Curry from the University of Colorado Boulder finally detected undoubtedly atmospheric signs of atmospheric spray.
It is, say the researchers, a crucial piece of the puzzle of the way Mars lost both its atmosphere and its water.
“These results provide a substantial step towards observation of the observation of the role of spraying in the loss of the atmosphere of Mars”, ” The team written in their newspaper“And, therefore, to determine the history of water and these implications for habitability over time.”
Atmospheric spray is one of the dominant mechanisms of atmospheric loss in the early solar system, when the sun was more brilliant and more active. This happens when the ions are accelerated by the electric wind of the solar wind in the atmosphere of a body – like Mars – which is not protected by a global magnetic field.
The effect is a bit like when a meteorite is slapped in a planet: the energy is transferred to the surrounding neutral world, by making it kick in a spray. But for spraying, some of the atoms and atmospheric molecules gain enough energy to reach the exhaust speed, and they leave, thrown into space in a new adventure.
It is difficult to observe this process on Mars. It requires a simultaneous observation of the neutral atoms thrown, and either the ions which struck the atmosphere, or the electric field which accelerated them. It also requires a simultaneous day and March night observationsdeeply in its atmosphere.
The only spaceship with equipment and orbital configuration for observations is nasa Maven. The researchers carefully placed themselves on the data collected by the spaceship since their arrival in orbit Mars in September 2014, seeking to find simultaneous observations of the solar electric field and an abundance of upper argon atmosphere – one of the sprayed particles, used as a tracer for the phenomenon.
It is a photo of the March surface taken by the Viking 1 orbiter in 1976.
It looks like something about a science fiction film you would see today.
(And yes, it’s * a smiling face in this crater …)
Credit: NASA / JPL-CALTECH, Treatment with Andrea Luck (@ Anderaluck.bsky.social)
– Paul Byrne (@ theplanetaryguy.bsky.social)) March 17, 2025 at 1:2 p.m.
They found that, above an altitude of 350 kilometers (217 miles), the densities of Argon vary depending on the orientation of the solar wind electric field, compared to the densities of Argon with lower altitudes which remain consistent.
The results have shown that the lighter isotopes of the Argon vary, leaving behind an excess of heavy argon – a divergence which is better explained by active spray. This is supported by the observations of a solar stormwhose outings arrived in March in January 2016. During this period, evidence of spraying became much more pronounced.
Not only does this support the conclusion of the team according to which the variations in density of the argon at high Martian altitudes are the result of spraying, but it demonstrates what conditions could have been like billions of years, when the sun was younger and more branch, undergoing a more frequent storm activity.
“We note that atmospheric spraying today is more than four times higher than previous predictions and that a solar storm can considerably increase the pulverized yield”, ” Researchers write.
“Our results confirm that spraying occurs on Mars today and could have been the main path of atmospheric escape in Mars during the first eras of our solar system when solar activity and extreme ultraviolet intensities were much higher.”
The results were published in Scientific advances.