Scientists Uncover New Insights into Mars' Ionosphere
On November 13, 2020, the European Space Agency deployed two spacecraft—Mars Express and the ExoMars Trace Gas Orbiter—to explore the Martian ionosphere more comprehensively. Using a novel technique called mutual radio occultation, these orbiters exchanged signals while passing behind Mars, allowing scientists to gather unprecedented data on this vital atmospheric layer. This method overcomes previous limitations caused by the relative positions of Mars, Earth, and the Sun, which hinder traditional radio measurements during certain times of the day. The new findings, published in the Journal of Geophysical
Research: Planets, refine our understanding of the electron density, temperature variations, and structure of Mars’ ionosphere, challenging earlier models. Notably, the research reveals that the main layers—M1 and M2—exhibit less fluctuation than previously thought, and that the M1 layer persists during midday hours, contrary to earlier assumptions.
A surprising discovery relates to temperature behavior: instead of peaking at midday, ionospheric temperatures are highest just before sunset. Solar heating alone cannot explain this; instead, wind-driven atmospheric dynamics appear to play a dominant role.
These insights are crucial for future communication strategies and atmospheric modeling, enhancing mission planning and scientific knowledge about Martian weather and plasma processes. The research opens new pathways to understanding planetary atmospheres and their interactions with solar radiation.
