The powerful solar wind had torn off the “tail” of the Earth’s magnetic field | Business

Dramatic changes in the solar wind alter the structure and dynamics of the magnetosphere. An example of such changes allows us to look at the behavior of other cosmic bodies, such as the moons of Jupiter and the outer planets.

Unprecedented observations of a rare phenomenon produced by a coronal mass ejection (CME) are reported. CMEs typically travel faster than the Alfvén speed, the speed at which vibrating magnetic field lines move through a magnetized plasma, which can vary depending on the plasma environment.

in 2023 the CME that occurred disrupted the normal configuration of the Earth’s magnetosphere for about 2 hours. To find out what happened, scientists analyzed data collected by NASA’s Magnetospheric Multiscale Mission (MMS).

in 2023 April 24 The MMS spacecraft observed that while the speed of the solar wind stream was high, the Alfvén speed during strong CMEs was even higher. Normally, the solar wind moves faster than the Alfvén speed. As a result of this anomaly, the “buffer” of the Earth’s magnetosphere temporarily disappeared, allowing the Sun’s plasma and magnetic field to directly interact with the magnetosphere. The tail of Earth’s “wind sock” has been replaced by structures called Alfvén wings, which connect Earth’s magnetosphere with the recently erupted region of the Sun. This junction acted as a highway for transporting plasma between the magnetosphere and the Sun.

The study says this unique CME event has provided new insights into how Alfvén wings form and evolve. A similar process may occur around other magnetically active bodies in the solar system and universe, and the researchers’ observations suggest that auroras on Jupiter’s moon Ganymede may also be caused by Alfvén wings.

The authors suggest a future search for similar Alfvén wing auroras on Earth.