These so-called “convective vortices,” similar to the sand whirlwinds that strike some deserts on Earth, are one of the primary weather phenomena on Mars, a dry planet with a very sparse atmosphere.
They form when there is a strong temperature difference between the soil and the air, and often get in the way of robotic exploration missions sent by humans. Also, the Jezero crater, where the mobile “Perseverance” robot has been operating since February 2021, witnesses many of these phenomena, but this vehicle manufactured by the US space agency “NASA” was not previously able to directly monitor its sound.
Fortunately, on September 27, a whirlwind 118 meters high passed over the robot’s head and its “SuperCam” instrument equipped with a microphone recorded the first sound from Mars immediately after its descent.
The data reached Earth a few days later.
“When we realized that we had the images from the camera as well as the data from the weather and acoustic sensors at the site, we felt as if we had hit the jackpot!”
“We hear the wind associated with the whirlwind, the moment it arrives, then everything disappears because we are in the eye of the vortex, and then the sound returns again when the microphone passes through the second wall,” added the planetary specialist at the Isai-Supero Institute in Toulouse, France, where the microphone was designed.
The microphone, in particular, transmitted a precise clicking sound that allows for “particle counting” in order to be able to study the structure and behavior of dust.
“The dust cycle on Mars and in the sky plays a very important role for the climate, just like the water cycle on Earth,” said Naomi Murdock.
The scientific official for the “Supercam” tool, Sylvester Morris, who participated in the study, indicated that the dust analysis makes it possible to “explore interactions” between the Earth and this very soft atmosphere, which was denser billions of years ago, allowing the presence of liquid water on the surface.
This new data would explain how dust is lifted from the surface of Mars, something scientists do not yet know.
“In some areas, tornadoes pass by, pulling dust and cleaning the robots’ solar panels in their path,” said Naomi Murdock.
In other regions, the cyclones pass without raising the dust, for an unknown reason, and “they are just moving air,” as is the case at the site where the American “Insight” probe operates, whose solar panels are “covered with dust” because they are unable to take advantage of these natural suction devices. .
Elucidating this mechanism may help to develop graphical models of “dust devils” to better predict them. On a larger scale, this could make it possible to predict huge dust storms that could cover the entire planet, similar to the scenario of the science fiction movie “The Martian”, which was released in 2015 and described by the scientist as “unrealistic”.
“We are in the process of improving our weather model. This is important for the maintenance of our spacecraft and for future human exploration missions,” said Sylvester Morris.
As for the contribution of these results to research on traces of extraterrestrial life, the physicist said, “One might think that studying the climate of Mars today has nothing to do with searching for traces of life billions of years ago. But the matter is complementary because the history of Mars witnessed severe climate change that made it move From a hot and humid climate (and therefore suitable for the emergence of life) to a completely dry and cold planet.