By Kevin
A new study suggests the moon has a previously unknown tidal force on the plasma ocean around Earth's upper atmosphere.
The study used 40 years of satellite data to track changes in the shape of the plasmasphere.
The plasmasphere is a dense, cool plasma blob in the inner region of Earth's magnetosphere, which protects from solar storms.
The moon's gravitational pull can distort the plasma ocean, causing it to rise and fall like ocean tides.
The moon was previously known to exert tidal forces on Earth's oceans, crust, and atmosphere.
The team analyzed data from 50,000 crossings of the plasmasphere by satellites to determine the effect of the moon on the plasma ocean.
The team found fluctuations in the shape of the plasmapause that followed daily and monthly patterns similar to ocean tides, indicating the moon as the cause.
The researchers think the interaction could help understand other parts of the magnetosphere, such as the Van Allen radiation belts, and have implications for tidal interactions in other celestial systems.
By Kevin