The large temperature variations on Mars can cause Perseverance's arm to expand or contract ever so slightly, which can disrupt the aim of the PIXL instrument. To counteract this, the hexapod automatically adjusts the instrument to position it extremely close to the rock without making contact. According to Allwood, precise adjustments in the range of micrometers are necessary to achieve the required accuracy. The instrument gets close enough to the rock's surface to make engineers nervous. Once PIXL is in place, another AI system takes over. It scans a small area of the rock, emitting thousands of X-ray beams to generate a grid of microscopic dots. Each dot provides information about the minerals' chemical composition. Minerals play a crucial role in unraveling key mysteries about Mars. Depending on the rock, scientists may be searching for carbonates, which could reveal how water contributed to the rock's formation, or phosphates, which could have served as nutrients for potential microbes in Mars' past. The scientists cannot predict which specific mineral each X-ray zap will uncover, but the instrument automatically pauses to collect more data when it detects certain minerals.

This action, known as a "long dwell, " is expanded as the system learns through machine learning, thereby increasing the list of minerals that PIXL can focus on. Thompson from JPL, who contributed to the software development, explains that PIXL is versatile and can be configured based on the scientists' current objectives. Mars provides an excellent testing ground for AI because of the regular daily communications that allow for adjustments to be made along the way. As future missions venture deeper into the solar system, there will be longer periods without communication compared to current Mars missions. Therefore, there is a significant interest in developing more autonomous capabilities for missions as they traverse and conduct scientific investigations to benefit humanity. Perseverance's mission on Mars has a primary goal of astrobiology, including the search for signs of ancient microbial life. The rover will also analyze the planet's geology and past climate, paving the way for future human exploration of Mars. Additionally, it will be the first mission to collect and store Martian rock and dust samples. Future NASA missions, in collaboration with the European Space Agency (ESA), are planned to retrieve these sealed samples from the Martian surface and return them to Earth for detailed analysis. The Mars 2020 Perseverance mission is part of NASA's Moon to Mars exploration strategy, which includes Artemis missions to the Moon to prepare for human exploration of Mars. JPL, managed by Caltech in Pasadena, California, is responsible for the construction and operation of the Perseverance rover. For more information about the Perseverance mission, please visit mars. nasa. gov/mars2020/.