If there is a planet that man has always dreamed of reaching, it is Mars. Our neighbor in the Solar System, like the Earth, It is a rocky planet, it has clouds, winds, a day of approximately 24 hoursseasonal weather patterns, polar ice caps, volcanoes, canyons and other familiar features.
And if that is not enough, when reviewing its present through astronomical observations, of spacecraft that orbit it or of rovers that analyze its atmosphere and surface, There are indications that billions of years ago Mars looked even more like Earth, with a denser and warmer atmosphere, rivers, lakes, flood channels and perhaps oceans.
And speaking of rovers that travel kilometers on the surface of the red planet, he Curiosity NASA has discovered unusually rocks rich in manganese oxide, a chemical that adds to the growing evidence that Mars, once habitable, may have had Earth-like oxygen levels and conditions conducive to life early in its historysay scientists.
Manganese is a mineral that the human body needs to stay healthy. You use it to produce energy and protect cells. The body also needs manganese to strengthen bones, for reproduction, blood clotting, and to maintain a healthy immune system.
AND NASA calls this material on Earth “an unsung hero in the evolution of life”. About 4 billion years ago on Earth, when no form of life had yet evolved, manganese was abundant in rocks and oceans. That allowed the existence of oxygen in geological history of our planet, which finally led to life existing today.
Today scientists know that the only known ways to produce manganese oxide involve abundant oxygen or microbial life. But there is no solid evidence for the former on Mars, nor the latter, leaving scientists baffled about how the chemical formed in the newly discovered rocks.
“Forming manganese oxide-rich rocks is easy to do on Earth because of microbes and oxygen, which [también se forma] because of the microbes, so everything points towards life,” he explained Patrick Gasda research scientist at the Álamos National Laboratory in New Mexico, near Los Angeles, USA.
“Of course, we have no evidence of life on Mars, so if we are trying to form oxygen in a completely abiotic system, our current understanding of Mars does not explain it,” added the expert.
The basis for Gasda lies in the fact that the Curiosity rover encountered heavily eroded rocks while rolling through the center of the Gale Crater, an ancient lake bed 154 kilometers wide that it has been exploring since arriving on Mars in 2012. Their discovery came when the rover’s ChemCam instrument “sniffed” for manganese oxide inside the rocks, vaporizing small pieces with a laser and then analyzing the resulting plasma cloud. The compound makes up almost half of the chemical composition of rocks, according to a new study published in the journal JGR Planets.
The researchers tried to find an explanation for this and noticed that the place where Curiosity found the new rocks was special. The rover had recorded an elevation change of 10 to 15 meters, which gave them the clue that something special was happening in that place. The texture of the rock where the new sandstones were found seems to have changed from “curved” to “flat”, a change that Gasda and his colleagues are interpreting as the channel of a river that It opens onto a lake.
“That means we are on the lake shore or near the lake shore. And that made the interpretation really challenging,” said the expert, who pointed out that this interpretation is uncertain due to the scarcity of data, which could be corroborated in future explorations with humans.
If the think tank’s hypothesis is correct, the rocks may have been dumped in the region when the river water slowed down as it entered the lake, similar to manganese oxide-rich rocks that have been found on the shores of lakes. shallow on Earth.
“These newly studied rocks are another line of evidence that liquid water ran on Mars in the past. And the fact that it was surely beneficial for life,” he said. Manasvi Lingam, astrobiologist at the Florida Institute of Technology who was not affiliated with the new research. “This work provides evidence in favor of habitability,” he concluded.
Faced with this theory, not yet corroborated, several experts cast their doubts on this statement. According to Jeffrey Catalano, professor of earth, environmental and planetary sciences at Washington University in St. Louis, who was not involved in the study, the presence of rusty rocks could help scientists understand whether Mars, like The Earth went through “a punctuated transition period” from a period with less oxygen to a period with more oxygen.
“However, the impact of manganese oxides on our understanding of this transition has been exaggerated, both here and in previous work,” he added.
Catalano was part of a 2022 study that found manganese oxide could easily form under Mars-like conditions without atmospheric oxygen. That research, which was based on laboratory experiments, showed that elements such as chlorine and bromine, which were abundant on early Mars, converted manganese dissolved in water into manganese oxide minerals. This finding offered an alternative to oxygen that could explain rocks like those recently discovered on Mars.
“There are several forms of life, even on Earth that do not need oxygen to survive,” Kaushik Mitra, a geochemist at the University of Texas at San Antonio, who led that study, said in a statement in 2022. “I considered it a ‘setback’ for habitability, except that there were probably no oxygen-based life forms,” the expert said.
A team of NASA scientists had found in 2023 evidence in meteorites that Mars and Earth had a similar origin, but then the two planets evolved quite differently.
Experts from the Astromaterials Exploration and Research Science Directorate at NASA’s Johnson Space Center were based on analyzes carried out on two Martian meteorites, and postulated that The water in the Martian interior originated from planetary building blocks similar to those that formed Earth. This finding implies that chondritic meteorites containing small granular minerals (not comets) are the source of water for terrestrial planets. The results of this research were published in the journal Earth and Planetary Science Letters.
The researchers also found that, unlike on Earth, Martian rocks containing atmospheric volatiles like water were not recycled deep into the planet’s interior. If that had been the case, the primordial water the researchers found would have been superimposed by water recycled from Mars’ atmosphere.
“There are competing theories that explain the diverse compositions of Martian meteorites,” said Tomohiro Usui of Tokyo, Japan, lead author of the paper and a former NASA/LPI postdoctoral fellow who led the research.
“Until this study there was no direct evidence that early Martian lavas contained material from the surface of Mars,” he added.
There is much controversy surrounding the origin, abundance and history of water on Mars. The sculpted canals of the Martian southern hemisphere speak clearly of flowing water, but that terrain is ancient. Consequently, planetary scientists often describe early Mars as “warm and wet” and modern Mars as “cold and dry.”
