Researchers led by the University of Iowa have learned how a type of aurora borealis forms on Mars. In a new study, physicists report a discrete shape of the aurora through the interaction of the solar wind and the crust in the southern hemisphere of Mars. Credit: CU / LASP
Scientists have learned how to form a discrete glow on Mars. In a new study, physicists report that the properties of the solar wind upstream, interacting with the magnetic fields of the crust found in the southern hemisphere of Mars, strongly influence the formation and properties of the Martian discrete radiance. The study was led by Zachary Girazian, an associate researcher in the Department of Physics and Astronomy at the University of Iowa.
Physicists led by the University of Iowa have learned how a kind of aurora borealis forms on Mars.
In a new study, physicists are studying a discrete radiance, a phenomenon of light in the sky that occurs mostly at night in the southern hemisphere of the Red Planet. Although scientists knew about the discrete radiance of Mars – which is also found on Earth – they were puzzled by how they formed. This is because Mars does not have a global magnetic field like Earth, which is a major trigger for the aurora borealis, also called the northern and southern lights of our planet.
Instead, physicists say, the discrete radiance of Mars is controlled by the interaction between the solar wind – a constant stream of charged particles from the sun – and magnetic fields generated by the crust in the southern latitudes of Mars. This is the nature of this localized interaction between the solar wind and the earth’s magnetic fields, which leads to a discrete glow, scientists have found.
“We have the first detailed study looking at how solar wind conditions affect the aurora borealis of Mars,” said Zachary Girazian, an associate researcher in the Department of Physics and Astronomy and author of the study. “Our main finding is that inside the strong field of the crust the speed of radiance depends mainly on the orientation of the magnetic field of the solar wind, while outside the strong field of the crust the speed of appearance depends mainly on the dynamic solar wind pressure.
This is an artistic representation of the atmosphere of Mars and the unstable evolution of NASA or the MAVEN spacecraft orbiting Mars. Credit: NASA / GSFC
The findings come from more than 200 observations of the discrete radiance of Mars from NASA’s Mars Atmosphere and Volatile EvolutionN (MAVEN) spacecraft. One of the instruments used to make the observations, the solar wind ion analyzer, is led by Jasper Halekas, an associate professor in the Department of Physics and Astronomy and co-author of the study.
“Now is a very fruitful and exciting time to explore the aurora borealis on Mars. “The database of discrete observations of aurora borealis that we have from MAVEN is the first of its kind, which allows us to understand the basic characteristics of aurora borealis for the first time,” Girazyan said.
Reference: “Discrete radiance of Mars: dependence on the conditions of the solar wind upstream” by Z. Girazian, NM Schneider, Z. Milby, X. Fang, J. Halekas, T. Weber, SK Jain, J.-C. Gérard, L. Soret, J. Deighan and CO Lee, March 27, 2022, JGR: Space Physics.DOI: 10.1029 / 2021JA030238
Contributing authors include Nick Schneider, Zacharia Milby, Xiaohua Fang, Sonal Kumar Jain, and Justin Dagan of the University of Colorado-Boulder; Tristan Weber of NASA’s Goddard Space Flight Center; Jean-Claude Gerard and Lucas Sore of the Universite de Liege in Belgium; and Christina Lee of the University of California, Berkeley.
NASA funded the study.
Add Comment