Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results from NASA’s MAVEN spacecraft. The metal ions can reveal previously invisible activity in the mysterious electrically charged upper atmosphere (ionosphere) of Mars.
“MAVEN has made the first direct detection of the permanent presence of metal ions in the ionosphere of a planet other than Earth,” said Joseph Grebowsky of NASA’s Goddard Space Flight Center in Greenbelt, Maryland and lead author of a new study detailing MAVEN’s results.
“Because metallic ions have long lifetimes and are transported far from their region of origin by neutral winds and electric fields, they can be used to infer motion in the ionosphere, similar to the way we use a lofted leaf to reveal which way the wind is blowing,” Grebowsky said. The new study was published April 10 in Geophysical Research Letters. (…)
The metal comes from a constant rain of tiny meteoroids onto the red planet. When a high-speed meteoroid hits the Martian atmosphere, it vaporizes. Metal atoms in the vapor trail get some of their electrons torn away by other charged atoms and molecules in the ionosphere, transforming the metal atoms into electrically charged ions.
MAVEN has detected iron, magnesium, and sodium ions in the upper atmosphere of Mars over the last two years using its Neutral Gas and Ion Mass Spectrometer instrument, giving the team confidence that the metal ions are a permanent feature. “We detected metal ions associated with the close passage of Comet Siding Spring in 2014, but that was a unique event and it didn’t tell us about the long-term presence of the ions,” Grebowsky said.. [More at links]