New study reveals unexpected interaction between Mars and the solar wind

Scientists from the Swedish Institute of Astrophysics (IRF) in Kiruna and Umeå University have discovered that under certain conditions the induced magnetosphere of Mars can degrade, their findings are published in a new study in the journal Nature.

An induced magnetosphere forms when a planet has no internal magnetic field and instead the planet’s atmosphere interacts directly with the solar wind, a stream of charged particles with embedded magnetic fields emanating from the Sun.

Scientists have used computer models and observations from scientific instruments such as the IRF’s Space Plasma and High Energy Atomic Analysis instrument (ASPERA-3) on the European Space Agency’s (ESA) Mars Express space probe and NASA’s Maven space probe, which orbit Mars.

“When the flow of solar wind protons aligns with the solar wind’s magnetic field, Mars’ induced magnetosphere degenerates. This magnetosphere degeneracy affects how much of Mars’ atmosphere is lost to space,” says Qi Zhang, a doctoral student at IRF and Umeå University, and lead author of the paper.

The ASPERA-3 instrument measures the flux of ions, electrons and neutral atoms in the space around Mars. During more than 20 years in Mars orbit, ASPERA-3 has made many fascinating observations of Mars, including continuous measurements of ion outflow from the planet.