New study in Physical Review Letters reveals how magnetic reconnection heats space plasmas

Scientists at the Swedish Institute of Space Physics (IRF) in Uppsala have confirmed how a powerful process in space, called magnetic reconnection, heats space plasmas. Their research, based on data from NASA’s Magnetospheric Multiscale (MMS) mission, was published in Physical Review Letters, a leading scientific journal, and now the study was highlighted by the editors and featured in the Physics magazine.

Magnetic reconnection is a natural process that occurs in most environments in the universe, including around black holes, solar flares, and in planetary magnetospheres, such as Earth’s. It works by rearranging magnetic field lines, which releases a large amount of energy and heat the plasma. Using instruments flying through Earth’s magnetosphere, the IRF team studied how this heating occurs.

Here’s how it works:

When positively charged heavier particles (called ions) break away from the magnetic field during reconnection, intense electric fields form to pull in the lighter negatively charged electrons. The fast-moving electrons then generate waves that rapidly heat the plasma, raising its temperature to ten times its original value.

This study confirms long-standing theories about how magnetic reconnection operates, providing scientists with a clearer understanding of how energy is converted in space plasmas. Understanding these processes helps researchers better explain everything from space weather around Earth to powerful events in distant solar systems.

About Magnetospheric Multiscale

Magnetospheric MultiScale (MMS) is a NASA mission consisting of four identically instrumented satellites launched from Kennedy Space Center in March 2015.

The satellites use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence.

In collaboration with the Alfvén Laboratory at the Royal Institute of Technology (KTH), the Swedish Institute of Space Physics (IRF) in Uppsala is responsible for sensor surfaces and test equipment for the SDP/FIELDS instrument, which measures electric fields. The project is led by the University of New Hampshire, USA.

Links

Electron Heating by Parallel Electric Fields in Magnetotail Reconnection- https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.215201

Physics viewpoint - https://physics.aps.org/articles/v18/108