Solar activity increases as the Sun approaches its maximum in its magnetic activity cycle, with brilliant explosions, dark sunspots, loops of plasma, and swirls of super-hot gas. The solar dynamo is responsible for this activity. At the beginning of each cycle (solar minimum), there is relatively little activity and few sunspots. Activity steadily increases until it peaks (solar maximum) before decreasing again to a minimum.
The most recent solar minimum occurred in December 2019, just two months before Solar Orbiter launched. Initially, the spacecraft’s early views showed that in February 2021 the Sun was still relatively calm. However, recent data from Solar Orbiter indicates that we are now approaching solar maximum, which is expected to occur in 2025. Solar Orbiter’s more recent views taken during a close approach to the Sun in October 2023 show a striking increase in solar activity, adding weight to theories that the maximum could arrive up to a year earlier than expected.
Solar Orbiter will help us predict the timing and strength of solar cycles, which is vital because 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 at around a million degrees Celsius. EUI helps scientists investigate mysterious heating processes occurring in the Sun’s outer regions. Since EUI views the Sun in ultraviolet light, which is invisible to human eyes, a yellow color has been added to help visualize our changing Sun. Solar Orbiter is an international collaboration between ESA and NASA operated by ESA. The Extreme Ultraviolet Imager (EUI) instrument is led by the Royal Observatory of Belgium