[Reading Science] 'Aurora and Satellite Failures'... Discovered the Cause of Ultra-Strong Solar Winds

Max Planck Institute for Solar System Research in Germany
Analysis of ESA Solar Orbiter Observation Results
Small-Scale Explosions of Superheated Gas as the Cause of Solar Wind

The sun emits solar wind, which has an enormous speed and contains many particles. The solar magnetic fields, radiation, and particles that reach Earth cause auroras and sometimes have such a significant impact that they can disable satellites or communication networks. Scientists have uncovered the cause of this powerful solar wind.

Solar Orbiter launched by the European Space Agency. Photo by ESA

The Max Planck Institute for Solar System Research in Germany announced on the 24th, through a paper published in the international journal Science, that small-scale explosions of superheated gases on the sun's surface are estimated to accelerate small molecules at speeds of hundreds of kilometers per second, generating the solar wind.

The research team used observations from the Solar Orbiter launched by the European Space Agency (ESA). They discovered a new form of powerful gas ejection in the solar atmosphere and named it "picoflare jets." "Pico" is a unit meaning approximately 10 to the power of 12 (one trillion). The name was given because the energy involved was about one trillionth of the largest flare the sun can emit.

ESA's Solar Orbiter captured these picoflare jets while passing over the sun's south pole in March last year, successfully producing high-resolution images. The distance was only 45 million kilometers from the sun, closer than Mercury, the planet nearest to the sun. The picoflare jets appear as dark streaks hundreds of kilometers long that emerge and disappear after 20 to 100 seconds. Although brief, these explosions emit energy equivalent to the amount consumed by 3,000 to 4,000 American households in one year.

The research team estimated that these small-scale gas ejections cause material to be expelled from the sun. This pushes a large number of particles into space, triggering the powerful solar wind. They also suggested that these gas ejections occur due to disturbances in the magnetic fields of the solar plasma, which reaches temperatures of one million degrees Celsius.

Researcher Lakshmi Pradeep Chitta explained, "We discovered the picoflare jet phenomenon in one coronal hole, which means it could occur anywhere on the sun." He added, "If that is the case, the hypothesis that small flares occurring throughout the sun supply sufficient resources to the solar wind is possible."

This research aligns with observations sent by NASA's Parker Solar Probe mission. In March, the Parker Solar Probe discovered small gas ejections in the lower layers of the solar atmosphere, which were also estimated to supply energy to the solar wind. Dan Seaton, a solar physics researcher at the Southwest Research Institute, said, "These observations help us paint a picture of the many phenomena contributing to solar activity."

Meanwhile, the sun has already reached or is approaching the peak of its approximately 11-year activity cycle. Many sunspots are appearing on the sun's surface, and large flares accompanied by radiation are frequent. Since July until this month, three X-class solar flares, the highest grade, have occurred. In particular, the solar flare on the 7th emitted radiation strong enough to disrupt the Global Positioning System (GPS).