NASA's Perseverance rover conducted an extensive study of dust that settles on samples of materials used in spacesuits. Observations were made over 1,645 Martian sols. Scientists discovered that among the recorded particles were both regular and ultrafine dust fractions—so small that they are theoretically capable of penetrating human lungs and entering the bloodstream. This discovery is significant for preparing future crewed missions to Mars, as prolonged exposure to such dust could pose health risks to astronauts. The research results will be published on Tuesday, October 27, in the Proceedings of the National Academy of Sciences. NASA specialists believe that the data obtained will help develop more effective protective measures and materials for spacesuits, as well as safety protocols for crews that may spend extended periods on the Martian surface in the future. The study underscores the importance of studying not only the planet's geology and climate, but also potential threats to the human organism from the local environment. Dust is one of the key challenges for long-term human habitation on Mars: it can damage equipment, reduce the efficiency of solar panels, and, as the new data shows, poses risks to the respiratory system. The information obtained by Perseverance adds to the growing body of knowledge about the Martian environment necessary for planning safe and sustainable missions with human participation.