NASA's Magnetospheric Multiscale (MMS) space weather mission has helped solve one of astrophysics' biggest questions – when a solar storm strikes our planet, where does its intense rain of energy go? MMS discovered electron magnetic reconnection, a new process much different from the standard magnetic reconnection that happens in calmer areas around Earth. The mission's four satellites orbit in a close-knit pyramid formation, mapping the zone's electron density on a millisecond timescale and providing a detailed description of their behaviour.
The discovery explains the behaviour of a chaotic zone at the edge of Earth's protective magnetic shell when it is showered with charged particles. In turn, the discovery lays fresh foundations for understanding similar turbulent hot-spots such as the one surrounding the Sun. Astronomers found that there are sub-atomic scale shifts in the turbulent swirl of electrons far above our planet's surface that effectively dissipates the energy that gets caught up in its writhing mess of magnetism.
Turbulence occurs everywhere in space: on the Sun, in the solar wind, interstellar medium, dynamos, accretion disks around stars, in active galactic nuclei jets, supernova remnant shocks and more. The Sun's corona is hundreds of times hotter than the visible surface beneath, and so far nobody has come up with a convincing explanation. One possibility is explosive eruptions called 'nanoflares'.
Knowing more about how magnetic fields reconnect in this ultra-hot zone might fill in the missing pieces that lead to a satisfactory answer. NASA's upcoming Solar Probe mission intends to collect crucial data by sweeping through the star's corona.
This research was published in Nature.
Credit for Image at Top of Page: (NASA’s Goddard Space Flight Center/Mary Pat Hrybyk-Keith)