As the Sun goes through its cycle of activity, which lasts around 11 years, we see more brilliant explosions and swirls of super-hot gas as it approaches its maximum in magnetic activity. This is caused by the ‘solar dynamo’, a process that generates the Sun’s magnetic field. At the beginning of this cycle, there is relatively little activity and few sunspots. Activity steadily increases until it reaches its peak, after which it decreases again to a minimum.
The most recent solar minimum was in December 2019, just two months before Solar Orbiter launched. The spacecraft’s early views showed that in February 2021 the Sun was still relatively calm. We are now approaching solar maximum, which is expected to occur in 2025. However, recent theories suggest that the maximum could arrive up to a year earlier than expected due to an increase in solar activity observed by Solar Orbiter during a close approach to the Sun in October 2023.
Solar Orbiter will help us predict the timing and strength of solar cycles, which is vital because solar activity can seriously affect life on Earth; extreme eruptions can damage ground-based electricity grids and disable orbiting satellites. The images were taken by Solar Orbiter’s Extreme Ultraviolet Imager (EUI) instrument, which reveals the Sun’s upper atmosphere, which has a temperature of around a million degrees Celsius. EUI helps scientists investigate the mysterious heating processes that occur in the Sun’s outer regions. Since EUI views the Sun in ultraviolet light, which is invisible to human eyes, the yellow color is added to help us visualize our changing Sun. Solar Orbiter is a space mission of international collaboration between ESA and NASA, operated by ESA. The Extreme Ultraviolet Imager (EUI) instrument is led by the Royal Observatory of Belgium.