A May 26, 2020 press release from NASA references a finding published
in Nature Astronomy yesterday on the global current systems of the Martian
induced magnetosphere and how they played a fundamental role in
atmospheric loss.
Quote:
Originally Posted by NASA
Five years after NASA’s MAVEN spacecraft entered into orbit around Mars, data from the mission has led to the creation of a map of electric current systems in the Martian atmosphere.
“These currents play a fundamental role in the atmospheric loss that transformed Mars from a world that could have supported life into an inhospitable desert,” said experimental physicist Robin Ramstad of the University of Colorado, Boulder. “We are now currently working on using the currents to determine the precise amount of energy that is drawn from the solar wind and powers atmospheric escape.” Ramstad is lead author of a paper on this research published May 25 in Nature Astronomy.
Earth has such current systems, too: we can even see them in the form of colorful displays of light in the night sky near the polar regions known as the aurora, or northern and southern lights. Earth's aurora are strongly linked to currents, generated by the interaction of the Earth’s magnetic field with the solar wind, that flow along vertical magnetic field lines into the atmosphere, concentrating in the polar regions. Studying the flow of electricity thousands of miles above our heads, though, only tells part of the story about the situation on Mars. The difference lies in the planets’ respective magnetic fields, because while Earth’s magnetism comes from within, Mars’ does not.
Planetary magnetic fields
Earth’s magnetism comes from its core, where molten, electrically conducting iron flows beneath the crust. Its magnetic field is global, meaning it surrounds the entire planet. Since Mars is a rocky, terrestrial planet like Earth, one might assume that the same kind of magnetic paradigm functions there, too. However, Mars does not generate a magnetic field on its own, outside of relatively small patches of magnetized crust. Something different from what we observe on Earth must be happening on the Red Planet.
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Full press release here including animation :-
https://www.nasa.gov/press-release/g...ctric-currents
Abstract Nature Astronomy
"The global current systems of the Martian induced
magnetosphere" by Ramstad et. al. :-
https://www.nature.com/articles/s41550-020-1099-y