Measured from the Moon, the shell of plasma that surrounds the Earth

The use of the lunar receiver made it possible to analyze the transition region between 1,000 and 8,000 kilometers above sea levela band poorly covered by ground-based radars and lower satellite orbits.

In this specific atmospheric zone the ionospheric and plasmaspheric dynamics are concentrated influence the propagation of radio frequencies, where the density of free electrons determines up to 60 percent of the night-time delay of positioning signalswith direct repercussions on the accuracy of telecommunications. To calculate the plasma density, the researchers quantified the Total Electronic Content (TEC) along the GPS and Galileo signal vectorscomparing the empirical values ​​with the Global Core Plasma Model (GCPM) simulations. Although the theoretical model has proven valid in reproducing the macroscopic morphology of the magnetosphere, LuGRE data highlighted systematic discrepancies: the model overestimates the electron density in the daytime phase and underestimates the real values ​​during the nighttime phasealso detecting subtle density structures and precisely defining the geometric boundary between dense and rarefied latitudes.

The results of this measurement campaign pave the way for the design of stable infrastructures for the study of space weathera critical factor in safeguarding satellite networks and global communications systems. The interaction between the monthly orbital motion of the Moon and the daily rotation of the Earth would allow a permanent receiver to map the plasma in four-dimensional mode at all latitudes and local times.

The first author of the study and first researcher at INGV, Claudio Cesaroni, underlined the scientific significance of the data collected: “For the first time we used the Moon as a point of view to observe the plasma surrounding the Earth, filling an observation gap that had existed for decadesThe interdisciplinary nature of the research allowed us to combine geophysical and engineering expertise to refine our understanding of the internal magnetosphere. Cesaroni himself specified the technical peculiarities of the analysis: “This work arises from a collaboration between geophysics and satellite navigation engineering. Earth-Moon geometry makes us particularly sensitive to higher altitudes, where the contribution of the plasmasphere is dominant and more difficult to measure with conventional instrumentsThe development of future permanent lunar stations will benefit from this approach, also supported by the INGV Earth Space Observations Center (COS).