ISRO has announced a significant discovery from the Chandrayaan-2 orbiter, revealing unexpectedly high electron densities in the lunar environment. This finding was made possible by analysing radio signals from the orbiter as it passed through the Earth's geomagnetic tail, a region known as the "geo tail."

According to ISRO, the Moon passes through earth’s extended magnetic field, or "geo-tail," for nearly four days in each orbit.

The study, published in The Astrophysical Journal - Letters, indicates that the Moon's ionosphere exhibits electron densities of approximately 23,000 electrons per cubic centimetre when it enters this region.

This density is comparable to that observed in the Moon's wake region and is nearly 100 times higher than on the sunlit side of the Moon.

The high electron densities challenge previous assumptions that the Moon's passage through the geo-tail would result in lower plasma densities due to free diffusion along Earth's magnetic field lines. Instead, scientists propose that remnant lunar crustal magnetic fields may be trapping plasma, preventing its diffusion and leading to localised enhancements in electron density.

To support this hypothesis, researchers used the Three-Dimensional Lunar Ionospheric Model (3D-LIM), which simulated plasma dynamics under different conditions.

These findings have significant implications for future lunar missions, as high plasma densities can affect radio communications, surface charging effects, and interactions with lunar dust. Understanding the lunar ionosphere's behaviour will be crucial for planning lunar habitats, especially in regions influenced by crustal magnetic fields.

The study marks a major step forward in unravelling the complex plasma environment around the Moon and highlights the continued impact of Chandrayaan-2's science mission in advancing lunar research.

PTI