The solar wind consists of charged particles, known as plasma, that continuously escape the Sun. It propagates outwards through interplanetary space, colliding with anything in its path. When the solar wind collides with Earth’s magnetic field, it produces the aurorae.

Although the solar wind is a fundamental feature of the Sun, understanding how and where it is generated near the Sun has proven elusive and has been a key focus of study for decades. Now, thanks to its superior instrumentation, Solar Orbiter has taken us an important step closer.

The data comes from Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument. Images of the Sun’s south pole taken by EUI on 30 March 2022 reveal a population of faint, short-lived features that are associated with small jets of plasma being ejected from the Sun’s atmosphere.

“We could only detect these tiny jets because of the unprecedented high-resolution, high-cadence images produced by EUI,” says Lakshmi Pradeep Chitta, Max Planck Institute for Solar System Research, Germany, and the principal author on the paper describing this work. In particular, the images were taken in the extreme ultraviolet channel of EUI’s high resolution imager, which observes million-degree solar plasma at a wavelength of 17.4 nanometres.

Of particular importance is the fact that analysis shows that these features are caused by the expulsion of plasma from the solar atmosphere.

Researchers have known for decades