ESA Solar Orbiter Discovers the Origins of Energetic Solar Particles

Launched in 2020 in partnership with NASA, the Solar Orbiter of the European Space Agency has given important insights into the sources of energetic particles emitted by the Sun, as well as provided detailed images of the poles of the Sun and traced the sources of the Solar Energetic Electrons (SEEs), which are important in understanding space weather that impacts Earth and satellites.

Mission Highlights        

The first spacecraft to image the poles of the Sun is Solar Orbiter and it is the closest mission to the Sun to date. It has ten scientific instruments that monitor features on the surface of the sun and the solar wind. The probe detected more than 300 bursts of energetic electrons between November 2020 and December 2022 and associated them with certain solar events.

Solar Energetic Electrons.

SEEs are the products of two solar phenomena:

• Solar flares - explosions on the surface of the Sun which result in the rapid emission of particles.
• Coronal Mass Ejections (CMEs) - huge releases of plasma and magnetic fields with high-energy particles that are emitted over a longer duration. CMEs are more dangerous to satellites, power systems and astronauts.

Tracing Particle Origins

Solar Orbiter flew through jets of energetic electrons and recorded their sources on the Sun. Observers have observed a time lag between the events on the Sun and their particles being detected due to particle travel and space turbulence. This was the first direct observation that connects space energetic electrons to their solar sources.

Space Weather implications.

The understanding of the origins of SEEs and CMEs is crucial in forecasting space weather phenomena that have the potential to disrupt communication, GPS and power grids. Findings enhance readiness to solar particle events and contribute to astronaut and space technology safety.

Future Goals

The Solar Orbiter will also continue to investigate the 11 year magnetic cycle of the Sun, the excessive heating of corona and the acceleration of solar wind. These studies will improve the understanding of the impact of solar activity on the space environment of Earth and will guide future space missions.