Astonishing Video Shows 2 Million Kilometer Helical Structure Emerge From The Sun

In 2020, the European Space Agency (ESA), with help from NASA, launched the Solar Orbiter on a mission to get the closest images of the Sun ever taken, as well as being the first spacecraft to observe its polar regions. The spacecraft is also studying the Sun’s atmosphere and solar wind – the stream of charged particles hurled out of the Sun into the Solar System – using six imaging instruments. Of these, the Mid-infrared ELT Imager and Spectrograph (Metis) provides the best view of the solar wind.

“Metis is a coronagraph: it blocks the direct light coming from the Sun’s surface to be able to see the much fainter light scattering from charged gas in its outer atmosphere, the corona,” ESA explains. 

“Metis is currently the only instrument able to see the solar wind’s twisting dance. No other imaging instrument can see – with a high enough resolution in both space and time – the Sun’s inner corona where this dance takes place.”

In a new study, researchers explain how the instrument captured a unique view of an enormous, twisting structure as it twisted and whirled out of the Sun “as if caught in a cyclone that extends millions of kilometers from the Sun” back on October 12, 2022.

“In this paper, we present observations by Metis during its perihelion passage of a striking helical radial structure that extended from 1.5 to 3 [times the radius of the Sun] and lasted for more than 3 hours,” the team wrote in the study. “To the best of our knowledge, these observations are unique, in that they appear to show directly the long-duration outflow of Alfvénic solar wind into the heliosphere.”

With one solar radius being 695,700 kilometers (432,288 miles), the structure extended up to 2,087,100 kilometers (1,296,864 miles). The twisting flow is driven by a phenomenon known as Alfvén waves.

“Plasmas exhibit behaviors similar to fluids and gases, but with added complexity of containing magnetic (and occasionally electric) fields. In 1942, Hannes Alfvén combined the mathematics of fluid mechanics and electromagnetism to predict that plasmas could support wave-like variation in the magnetic field, a wave phenomenon that now bears his name, Alfvén waves,” NASA’s Visualization Studio explains.

“Like conventional fluids, plasmas can support waves, but with more variety than in conventional fluids. The waves initially proposed by Alfvén are considered ‘basic’. They have a characteristic that they are compressional, which means that magnetic field variation of the Alfvén waves is in the direction of the wave motion. Charged particles moving through a plasma with these waves have very little alteration of their trajectory.”

According to the team, the coronal mass ejection and helical structure were the result of an eruptive polar crown prominence.

“The observed features forming the helical structure are likely the result of bursty dense outflows and closed-field twist launched by interchange reconnection occurring in the wake of a jet-like CME [coronal mass ejection],” the team added. “An important finding is the long duration of the helical outflows, which persist until well after the initial eruption.”

While this particular structure was gigantic in scale, the team believes that this process may be a universal feature on smaller jets too. However, it is unclear whether these outflows would escape the Sun and contribute to the solar wind, or fall back into the chromosphere. More study is needed by the Solar Orbiter, and other Sun-monitoring craft like ESA’s Proba-3 mission.

The study is published in The Astrophysical Journal.