Magnetic reconnection event monitored directly for the first time

Space.com : A magnetic reconnection is an explosive release of protons and electrons that occurs when plasma from the Sun collides with a region of Earth’s magnetosphere that has an oppositely directed magnetic field. The radiation released poses a threat to astronauts and satellites in orbit and to electrical systems and nuclear fusion experiments on the ground. But until recently, magnetic reconnection was studied only via theory and in laboratories. NASA’s Magnetospheric Multiscale (MMS) mission—a set of four satellites in orbit around Earth—has now provided the first direct observations of those events. The satellites, which are each equipped with 25 of the fastest sensors NASA has put into orbit, take readings every 30 ms to track the motion of electrons. On 16 October 2015 MMS passed directly through a magnetic reconnection region, where the local magnetic field dropped to nearly zero, ions traveled in opposite directions, and electrons got accelerated by a strong electric field. The satellites detected a spike in the electric power generated by the electrons, a predicted behavior that had not been seen before. The mission research team next plans to move the satellites closer together so they can all enter a magnetic reconnection region simultaneously.