Experiments and measurements showed that man-made particles from ferrohydrite, an iron-containing mineral that occurs on Earth as a result of interactions of volcanic rocks with cold liquid water, were most similar to Martian dust.
MOSCOW, February 25. /tass/. American and European planetary scientists have found evidence in the images from the ExoMars-TGO probe that the dust particles that give Mars its characteristic red color arose as a result of complex chemical processes with the active participation of water. This once again indicates the long-term existence of reservoirs on ancient Mars, the press service of the European Space Agency (ESA) reported.
"Mars is still the red planet, but our understanding of why this is so has changed dramatically. Our analysis shows that the ferrohydrite particles that make up Martian dust could only have originated in the presence of liquid water. This suggests that Mars acquired its characteristic "rusty" color much earlier than we thought in the past," said a researcher at Brown University. Adomas Valantinas, whose words are quoted by the ESA press service.
As Valantinas noted, scientists have been interested for several hundred years in how Mars acquired its characteristic red-brown color. In the past, scientists believed, based on the results of measurements by ground-based telescopes and the first orbital missions, that the red color of Mars is due to the fact that the dust on its surface consists of the iron mineral hematite. It forms in an anhydrous environment, which is why scientists believed that Mars "rusted" after its oceans disappeared.
European and American planetary scientists have discovered the first physical evidence of the fallacy of this hypothesis when studying about two hundred images taken by the CaSSIS camera aboard the ExoMars-TGO probe during observations of the Martian atmosphere during several dust storms. The analysis carried out by the scientists helped them determine the size of dust particles, study their spectral characteristics and clarify how they interacted with light at different wavelengths.
Based on this information, the scientists tried to create an iron-containing material with similar characteristics in the laboratory. Their experiments and measurements showed that man-made particles from ferrohydrite, an iron-containing mineral that occurs on Earth as a result of interactions of volcanic rocks with cold liquid water, were most similar to Martian dust.
According to scientists, such a scenario of the formation of Martian dust particles is another evidence that significant reserves of liquid water have been present on Mars for a long time. The researchers hope that their theory will be confirmed by analyzing Martian dust samples that are planned to be collected and delivered to Earth as part of future ESA and NASA missions.
About the ExoMars project
The joint Russian-European ExoMars project included two parts - the ExoMars-TGO orbital probe, equipped with Russian and foreign scientific instruments for exploring the Martian atmosphere, as well as the Kazachok descent module and the Rosalind Franklin rover. The orbital part of the mission was successfully delivered to Mars in 2016, while the launch of the second half of ExoMars was canceled by the decision of the European side in early 2022 due to the events in Ukraine.
