The Moon may play a major role in maintaining Earth's magnetic field
The Earth's magnetic field permanently protects us from the charged particles and radiation that originate in the Sun. This shield is produced by the geodynamo, the rapid motion of huge quantities of liquid iron alloy in the Earth's outer core. To maintain this magnetic field until the present day, the classical model required the Earth's core to have cooled by around 3 000 °C over the past 4.3 billion years. Now, astronomers suggest that, on the contrary, its temperature has fallen by only 300 °C. The action of the Moon, overlooked until now, is thought to have compensated for this difference and kept the geodynamo active. Ref. Source 6y.
Space mission first to observe key interaction between magnetic fields of Earth and sun
Physicists have now provided the first major results of NASA's Magnetospheric Multiscale (MMS) mission, including an unprecedented look at the interaction between the magnetic fields of Earth and the sun. The article describes the first direct and detailed observation of a phenomenon known as magnetic reconnection, which occurs when two opposing magnetic field lines break and reconnect with each other, releasing massive amounts of energy. Ref. Source 8d.
Researchers in Antarctic discover new facets of space weather
A team of National Science Foundation (NSF)-supported researchers at the Virginia Polytechnic Institute and State University (Virginia Tech) discovered new evidence about how the Earth's magnetic field interacts with solar wind, almost as soon as they finished installing six data-collection stations across East Antarctic Plateau last January. Ref. Source 3k.
Just what sustains Earth's magnetic field anyway?
Earth's magnetic field shields us from deadly cosmic radiation, and without it, life as we know it could not exist here. The motion of liquid iron in the planet's outer core, a phenomenon called a 'geodynamo,' generates the field. But how it was first created and then sustained throughout Earth's history has remained a mystery to scientists. New work sheds light on the history of this incredibly important geologic occurrence. Ref. Source 3v.
'Space tsunami' causes the third Van Allen Belt
Earth's magnetosphere, the region of space dominated by Earth's magnetic field, protects our planet from the harsh battering of the solar wind. Like a protective shield, the magnetosphere absorbs and deflects plasma from the solar wind which originates from the Sun. Extreme space weather storms can create intense radiation in the Van Allen belts and drive electrical currents which can damage terrestrial electrical power grids. Earth could then be at risk for up to trillions of dollars of damage. Ref. Source 1p.