The aurora borealis is a light-in-the-sky display that occurs predominantly at night in Mars’ southern hemisphere. While their existence has long been known, scientists have been puzzled as to how they develop because Mars lacks the global magnetic field that Earth has, which is the primary generator of aurora on our lovely planet.
According to new research, aurora on Mars is caused by the interplay between the solar wind and magnetic fields generated by the crust at southern latitudes on the Red Planet.
The formation of a type of aurora on Mars has been discovered by researchers. The researchers discovered discrete auroras caused by the interaction of the solar wind and the crust of Mars’ southern hemisphere. The formation of a type of aurora on Mars has been discovered by physicists led by the University of Iowa.
Our main finding is that inside the strong crustal field region, the aurora occurrence rate depends mostly on the orientation of the solar wind magnetic field, while outside the strong crustal field region, the occurrence rate depends mostly on the solar wind dynamic pressure.Zachary Girazian
The physicists investigated distinct aurora, a light-in-the-sky phenomenon that occurs primarily at night in Mars’ southern hemisphere. While scientists were aware of discrete auroras on Mars, which also occur on Earth, they were unaware of how they evolved. This is due to Mars’ lack of a worldwide magnetic field, which is a major trigger for aurora, also known as the northern and southern lights on Earth.
Instead, the scientists find that discrete aurora on Mars are driven by the interplay of the solar wind – the continual jet of charged particles from the sun – and magnetic fields formed by the crust at southern latitudes on Mars. The scientists discovered that the nature of this limited interaction between the solar wind and the crustal magnetic fields causes discrete aurora.
“We have the first extensive study looking at how solar wind conditions affect aurora on Mars,” says Zachary Girazian, associate research scientist in the Department of Physics and Astronomy and the study’s corresponding author.
“Our main finding is that inside the strong crustal field region, the aurora occurrence rate depends mostly on the orientation of the solar wind magnetic field, while outside the strong crustal field region, the occurrence rate depends mostly on the solar wind dynamic pressure.”
To reach this result, the researchers had to examine over 200 observations of discrete aurora on Mars made by the NASA-led Mars Atmosphere and Volatile Evolution (MAVEN) satellite using a tool called the Solar Wind Ion Analyzer. This instrument measures the solar wind and magnetosheath proton flow around Mars and constrains the nature of solar wind interactions with the upper atmosphere.
The conclusions are based on more than 200 observations of distinct aurora on Mars by the NASA-led Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite. The Solar Wind Ion Analyzer, one of the equipment used to conduct the observations, is supervised by Jasper Halekas, associate professor in the Department of Physics and Astronomy and co-author on the study.
“Now is a very fruitful and exciting time for Mars aurora research. The MAVEN database of discrete aurora observations is the first of its type, allowing us to comprehend basic aurora aspects for the first time “Girazian claims.
According to the researchers, they intend to give data that will aid the international scientific community in creating a global weather map for Mars, understanding the planet’s weather cycles, and tracking the transport of hydrogen and oxygen through the different layers of the atmosphere.
NASA funded the research.