🌕 A magnetic bridge between Earth and the Moon revealed

Moon dust may contain fragments of our planet's history. Scientists are exploring this interesting lead, examining how materials from Earth's atmosphere could have traveled to our natural satellite.

A recent analysis shows that the magnetic field surrounding our planet acts as an invisible bridge to space. Instead of retaining all gases, it allows some light elements to escape when the solar wind strikes the upper layers of the air. These charged particles then travel along the lines of this field that extend very far, some reaching the lunar orbit. Consequently, this phenomenon, which has been occurring for billions of years, could explain the presence on the Moon of materials from home.


The soil samples brought back by the Apollo missions in the 1970s served as the starting point for this study. Scientists detected volatile elements such as nitrogen, water, or carbon dioxide in them. Some of it naturally comes from the solar wind, but the measured quantities, particularly for nitrogen, are too high for this sole origin.

Computer simulations conducted by a team at the University of Rochester provide an explanation. They compared two configurations: an ancient Earth without a magnetic shield and our current planet. Against all expectations, the transfer of particles to the Moon turns out to be more efficient in the modern scenario. With an active magnetic field, the solar wind more easily strips ions from the atmosphere, which are then guided to deep space where the Moon orbits.

This observation opens an unexpected historical perspective. The lunar regolith could thus preserve a chemical trace of Earth's atmosphere through the ages. By studying these deposits, it might be possible to trace the evolution of the air we breathe, the oceans, and the climate over extremely long periods, opening a unique window into the distant past of our planet.

Moreover, this slow accumulation has practical implications for the future of space exploration. The deposited volatile elements, such as water or nitrogen, represent potential resources for future lunar bases. They could be used for life support or fuel production, thereby reducing the need to bring everything from Earth and making a sustainable human presence more feasible.

The results of the study published in Communications Earth & Environment could also apply to other worlds. The described mechanisms help understand how planets like Mars, which once had a magnetic field and a thicker atmosphere, could have lost some of their air. Understanding these atmospheric escape processes helps to identify the conditions that make a planetary environment hospitable or not over time.