Aside from sunlight, the Sun sends out a gusty stream of particles called the solar wind. The ESA-led Solar Orbiter mission is the first to capture on camera this wind flying out from the Sun in a twisting, whirling motion. The solar wind particles spiral outwards as if caught in a cyclone that extends millions of kilometres from the Sun.
Solar wind rains down on Earth’s atmosphere constantly, but the intensity of this rain depends on solar activity. More than just a space phenomenon, solar wind can disrupt our telecommunication and navigation systems.
Solar Orbiter is on a mission to uncover the origin of the solar wind. It uses six imaging instruments to watch the Sun from closer than any spacecraft before, complemented by in situ instruments to measure the solar wind that flows past the spacecraft.
This video was recorded by the spacecraft’s Metis instrument between 12:18 and 20:17 CEST on 12 October 2022. 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.
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. (Soon, however, the coronagraph of ESA’s Proba-3 mission might be able to see it too!)
The research paper that features this data, ‘Metis observations of Alfvénic outflows driven by interchange reconnection in a pseudostreamer’ by Paolo Romano et al. was published today in The Astrophysical Journal.
Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA.
[Technical details: The starting image of the video shows the full view of Solar Orbiter’s Metis coronagraph in red, with an image from the spacecraft’s Extreme Ultraviolet Imager in the centre (yellow). Zooming to the top left of this view, we see a video derived from Metis observations. The vertical edge of the video spans 1 274 000 km, or 1.83 solar radii. The contrast in the Metis video has been enhanced by using a ‘running difference’ technique: the brightness of each pixel is given by the average pixel brightness of three subsequent frames, minus the average pixel brightness of the three preceding frames. This processing makes background stars appear as horizontal half-dark, half-light lines. Diagonal bright streaks and flashes are caused by light scattering from dust particles close to the coronagraph.]