Strong solar flare sent particles from Earth to the Sun
A powerful solar flare in April 2023 triggered a rare phenomenon on Earth. NASA observed a particle highway with two-way traffic.
Artistic representation of an aurora-like phenomenon above the sun.
(Image: NASA)
A powerful solar flare that caused auroras as far south as the USA on April 24, 2023, has also allowed scientists to observe another rare phenomenon: For about two hours, not only did particles fly from the sun to Earth as a one-way street, but a path was also opened up in the opposite direction. The US space agency NASA has now reported on this particle highway.
Certain conditions were necessary for the bidirectional particle flow. The intensity of the solar flare ensured that the Earth was completely enveloped in a cloud of particles. As a result, part of the Earth's magnetic shield briefly dissolved. As a result, the magnetic field of the solar flare merged with that of the Earth. While people on the surface were still protected by the atmosphere, particles trapped in the Earth's magnetic field were able to escape and took the opposite route - from the Earth to the sun.
More common on other planets
Scientists refer to these particle highways as "Alfvén wings". On Earth, they are a rare phenomenon. In other corners of the solar system, however, they can be observed regularly, for example on the moons of Jupiter. This is how particles from the moons Io and Ganymede reach Jupiter, where they cause ultraviolet auroras.
NASA observed the events as part of its Magnetospheric Multiscale Mission (MMS). The research project comprises four identical satellites, which are located in a highly elliptical orbit around the Earth. NASA is using them to investigate the interaction between the magnetic fields of the Earth and the Sun.
New insights into solar winds
Theoretically, according to NASA, the particles from Earth that hit the sun could also have caused auroras there - in practice, of course, this is impossible because they are far too weak to be visible there. For the scientists, however, the observations provided new starting points for understanding solar wind and how it affects the Earth.
(mki)