A gigantic solar eruption was registered on the far side of the Sun on 5 September by NASA's Solar Terrestrial Relations Observatory (STEREO-A) spacecraft. The enormous coronal mass ejection belonging to the type known as a halo CME sent a radiation storm out across the solar system.
This type of expulsion of plasma and magnetic field from the Sun's corona usually manifests itself in an expanding halo of hot gas spewing out around the entire Sun. The eruption is believed to have taken place in a sunspot region called AR 3088.
As the CME occurred on the far side of the Sun, it is heading away from Earth, ruling out any disruptive effects that a solar storm could wreak on the surface of our planet. Large eruptions interfere with the Earth's magnetic field, and radio communication and power grids can be affected.
‘Solar Pummeling’
The Solar Orbiter, which is at present near the planet Venus, found itself in the massive solar eruption’s path after a gravity assist maneuver on 4 September that brought it 4.5Mln kilometers closer to the Sun.
Solar Orbiter, an international cooperative mission between the European Space Agency (ESA) and NASA, is the most complex scientific laboratory ever to have been sent to the Sun. The spacecraft is designed to withstand and measure violent solar phenomena, including the Sun's violent eruptions.
"This is no run-of-the-mill event. Many science papers will be studying this for years to come… I can safely say the 5 September event is one of the largest (if not THE largest) Solar Energetic Particle (SEP) storms that we have seen so far since the Solar Orbiter launched in 2020," solar physicist George Ho of the Johns Hopkins Applied Physics Laboratory told SpaceWeather.
An earlier CME on 30 August had been registered prior to the gravity assist maneuver for the Orbiter.
Solar Orbiter was launched from Cape Canaveral on 9 February 2020 on a mission planned to last seven years. It is at present following an elliptical orbit around the Sun. Using gravity assists from Venus and Earth, it is gradually lifting itself out of the ecliptic plane to reach an angle of 24 degrees above the Sun’s equator enabling it to capture the first ever images of the Sun’s north and south poles. It carries a scientific payload of 10 different instruments, combining high-resolution telescopes with measurements from the environment directly surrounding the spacecraft.
Together with NASA’s Parker Solar Probe it has enabled scientists to study the Sun from a closer vantage point than any spacecraft before.
The Sun undergoes a cycle of varying activity levels, from low to high, observed in sunspot and coronal hole activity. Currently, the Sun is in the escalating stage of its activity cycle, expected to peak in July 2025.
Some of the biggest solar flares swooped over our planet this year, in the months since the spring, prompting radio blackouts in some parts of the world, according to the website SpaceWeather.com.