Privileged Planet: moon causes magnetosphere tides (Introduction)

by David Turell , Monday, February 06, 2023, 17:19 (657 days ago) @ David Turell

The magnetic field around Earth has moon caused tides:

https://www.livescience.com/plasmasphere-moon-tidal-force?utm_term=C3CFD69C-A485-4C10-9...

"In the study, published Jan. 26 in the journal Nature Physics(opens in new tab), scientists used more than 40 years of data collected by satellites to track the minute changes in the shape of the plasmasphere, the inner region of Earth's magnetosphere, which shields our planet from solar storms and other types of high-energy particles.

"The plasmasphere is a roughly doughnut-shaped blob of cool plasma that sits on top of Earth's magnetic field lines, just above the ionosphere, the electrically charged part of the upper atmosphere. The plasma, or ionized gas, in the plasmasphere is denser than the plasma in the outer regions of the magnetosphere, which causes it to sink to the bottom of the magnetosphere. The boundary between this dense sunken plasma and the rest of the magnetosphere is known as the plasmapause.

"'Given its cold, dense plasma properties, the plasmasphere can be regarded as a 'plasma ocean,' and the plasmapause represents the 'surface' of this ocean," the researchers wrote in the paper. The moon's gravitational pull can distort this "ocean," causing its surface to rise and fall like the ocean tides.

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"The satellite crossings occurred between 1977 and 2015, and during this period, there were four complete solar cycles. This information allowed the team to factor in the role of solar activity on Earth's magnetosphere. Once the sun's influence was accounted for, it started to become clear that fluctuations in the shape of the plasmapause followed daily and monthly patterns that were very similar to the ocean's tides, indicating that the moon was the most likely cause of the plasma tides.

"The researchers are unsure exactly how the moon causes the plasma tides, but their current best guess is that the moon's gravity causes perturbations in Earth's electromagnetic field. But further research is needed to tell for sure."

Comment: the Earth is a planet with just one moon that exerts all sorts of beneficial effects on us. Not by chance.