The Sun produced its largest solar flare since October 2017 over the weekend, which could be an indication that the sun’s solar cycle is becoming more active.
Such periods of activity can cause interference with radio equipment or satellites in space.
A collection of sunspots, which are dark areas of the sun signifying complex magnetic fields, were spotted by a Nasa spacecraft. On May 29, a relatively small solar flare came from these sunspots, sending harmful radiation into the atmosphere.
This flare is classified as M-class, which represents the middle in terms of solar flare strength – more powerful than C-class flares, but not as powerful as X-class flares, which can cause radio blackouts.
Each class is ten times as powerful as before, divided into five classes: A-class, B-class, C-class, M-class, and X-class. Even if a flare reaches X-class, there are ten classifications within that measurement, each ten times more powerful than the one previously, Nasa says. During the last solar maximum in 2003, the sensors cut out at X28.
This M-class flare did reportedly cause a small radio blackout, and was followed b a smaller C-class flare approximately three hours later. Over the past 48 hours, it has also been recorded that smaller B-class solar flares have been seen on the Sun too.
Although this flare was not strong enough to pass the marker at which point the NOAA (National Oceanic and Atmospheric Administration) would have to issue a warning for space weather forecasts, since the sun has been in a ‘solar minimum’ this could be a sign that our closest star is becoming more active.
The Sun has a natural 11-year cycle, where its activity increases and decreases. Strong activity from the Sun can send eruptions of energy into space with effects seen on Earth, including the aurora or interfere with radio communications and – in extreme cases – affect energy grids.
Scientists need to know when these solar cycles are occurring in order to protect the planet’s radio communications, as well as ensuring the safety of astronauts and satellites outside of the Earth’s atmosphere, because of the damage that they can have on electronics.
The task is a long one: scientists need six months of solar observations and sunspot measurements in order to know when a minimum has occurred, and it could take another six months or even a year after that to know when it is passed.