NASA discovers fast neutrons emitting from Sun's outer layer

NASA's MESSENGER spacecraft has discovered part of the outer layer of the Sun that is sending out modestly energetic subatomic particles called fast neutrons, which flowed past Mercury into space.

The researchers said that such charged particles twirl and gyrate around the magnetic field lines created by the vast magnetic systems that surround the Sun and Earth. Neutrons, however, not being electrically charged, travel in straight lines from the flaring region and can carry information about flare processes unperturbed by the environment through which they move.

Information provided by neutrons can be used by scientists to decipher one aspect of the complicated acceleration processes that are responsible for the creation of solar energetic particles.

David Lawrence of the Johns Hopkins Applied Physics Lab said that to understand all the processes on the Sun they look at as many different particles coming from the Sun as they can - photons, electrons, protons, neutrons, gamma rays - to gather different kinds of information.

Lawrence added that they can observe charged particles from the Sun closer to Earth we can, but analyzing them can be a challenge as their journey is affected by magnetic fields.

The researchers said that these neutrons form an exosphere above the corona that decay to a large swarm of equally energetic protons that in turn, expand along the magnetic field that is carried by the expanding solar atmosphere into interplanetary space.

The study was published in Journal of Geophysical Research: Space Physics.