Cluster hears the heartbeat of magnetic reconnection

For the first time, scientists have resolved the detailed structure of the core region where magnetic reconnection takes place in the magnetosphere of Earth using unprecedented wave measurements...

...In most cosmic environments, matter is not made up of neutral atoms and molecules, but rather of electrically charged particles and ions. This ionised state of matter, called plasma, is permeated by electric and magnetic fields caused by local inhomogeneities in the distribution of particles and ions...

... Magnetic reconnection is ubiquitous in the Universe. The phenomenon, which occurs in plasma, is triggered by microscopic processes and causes macroscopic effects: magnetic field lines from different domains collide and later assume a different configuration.

Magnetic reconnection produces rapid and global changes to the arrangement of a magnetic environment - for example, the magnetosphere of Earth. This process is an efficient mechanism to convert energy stored in the magnetic field to kinetic energy...

...Magnetic reconnection starts with two colliding flows of plasma whose magnetic fields are aligned along opposite directions: when pushed together, these create a thin sheet of current. As plasma keeps flowing towards this sheet from both sides, particles are accelerated and eventually released via two jets. This creates an X-shaped transition region, with a 'separatrix' region that divides the inflowing plasma from the outflows of highly energetic particles...

...By making high-resolution measurements of the electric and magnetic fields, WBD allows scientists to probe the structure of the plasma through waves, rather than particles...

... In future studies, the scientists plan to investigate if and how these electrostatic waves, which are confined to the magnetic reconnection region, might produce electromagnetic waves, able to propagate over much longer distances.

This would allow a comparison between Earth's magnetic environment and the many different sites where magnetic reconnection occurs, ranging from the corona of the Sun, to the accretion discs around forming stars, to plasma created in the laboratory.