Nasa’s Maven space probe has detected the presence of electrically-charged metal ions in Mars’s ionosphere.
The probe has detected iron, magnesium and sodium ions over the last two years leading researchers to believe they hold a permanent presence.
Maven (Mars Atmosphere and Volatile EvolutioN mission) is exploring the Red Planet’s upper atmosphere to determine just how the planet transformed from one that could’ve supported life to the barren place it is today.
Researchers say the metal comes from tiny meteoroids raining down on Mars as, when they hit the planet’s atmosphere, they vaporise. Some of the metal atoms in the vapour trail then transform into electrically-charged ions after their electrons are lost in the ionosphere.
Meteor showers are common throughout the solar system with metal ion layers having been detected in the Earth’s upper atmosphere too. However, the metal ions found at Mars provide the first conclusive evidence that metal ions exist permanently on other planets too.
“Observing metal ions on another planet gives us something to compare and contrast with Earth to understand the ionosphere and atmospheric chemistry better,” said Joseph Grebowsky of Nasa’s Goddard Space Flight Centre in Greenbelt, Maryland.
