Sun’s Coronal Mass Ejection Bombards Earth, Alters Magnetic Field: Here’s How

The intense solar wind streams striking Earth’s magnetosphere have led to significant changes. These solar winds have reshaped the sun-facing side of the magnetosphere, known as the bow shock, and stretched the magnetic field into a windsock-like shape with a long tail on the night side.

The solar winds underwent dramatic changes, altering the dynamics and structure of the magnetosphere.

Powerful CMEs Disrupting Earth’s Magnetosphere

In an article published in Geophysical Research Letters, Li‐Jen Chen and colleagues reported unprecedented observations of a rare phenomenon created during a coronal mass ejection (CME).

It was noted that CMEs move faster than the Alfvén speed, which is the speed at which vibrating magnetic field lines travel across magnetized plasma, varying with the plasma environment.

In 2023, a CME disrupted Earth’s magnetosphere’s normal configuration for nearly two hours.

Researchers analyzed observations from NASA’s Magnetospheric Multiscale Mission (MMS). On April 24, 2023, the MMS spacecraft observed that despite the solar wind’s high streaming speed, the Alfvén speed noticed during the strong CME was even higher. Typically, solar wind travels faster than the Alfvén speed.

This anomaly caused Earth’s bow shock to temporarily disappear, allowing the plasma and magnetic field from the Sun to interact directly with the magnetosphere.

Impact of CMEs on Earth’s Windsock Tail

Scientists observed that Earth’s windsock tail was replaced by structures called Alfvén wings, which formed a connection between Earth’s magnetosphere and the recently erupted region of the Sun. This connection acted like a highway, transporting plasma between the Sun and the magnetosphere.

The unique CME event provided new insights into the formation and evolution of the Alfvén wings, according to the authors.

A similar process can occur near other magnetically active bodies in our solar system and universe. The researchers suggested that auroras on Jupiter’s moon, Ganymede, were formed due to these Alfvén wings.