The Sun is now beginning to approach the peak of its 11-year activity cycle. A period that generally coincides with a substantial increase in the rate and intensity of phenomena such as solar flares, those extremely intense X-ray and gamma-ray discharges associated with the breakdown of a magnetic field line on the surface of the star. And after Spaceweather.coma site specializing in monitoring space weather, the star has just issued the most powerful solar flare since the start of the current cycle.
Solar flares are classified using a somewhat particular nomenclature. It begins with a letter (A, B, C, M or X) which designates the power category. A designates the smallest; Conversely, X designates the most violent eruptions. The official definition explains that they are likely to “ trigger planet-wide radio blackouts and prolonged radiation storms “. This letter is accompanied by a number that represents the magnitude of the eruption within that category. The higher the number, the more intense it is.
Two major eruptions in one week
The latest solar flare originated from a sunspot in the AR3842 group — a location that already made headlines on October 1 by emitting a powerful classified flare X 7,1. It was therefore an extremely energetic phenomenon, but not as much as the one that happened yesterday, October 3: we were entitled to a new major eruption, this time classified X 9.05.
Solar flares of this intensity are rare; specialists have only recorded a handful since the start of the millennium. They are also particularly violent. As a reminder, they are described using a logarithmic scale, like the Richter scale which classifies earthquakes; this new episode is therefore much more intense than the one which took place at the start of the week. In fact, it even inherits the 15th place in the modern database of SpaceWeatherLiveanother site specializing in referencing these phenomena.
Superb auroras…
These two episodes also gave rise to what we call coronal mass ejections — vast plasma bubbles propelled at very high speed. And it just so happens that these two objects have headed towards Earth. Our planet will therefore undergo two floods of high energy radiation.
These charged particles will interact with the Earth’s magnetic field and transfer part of their energy to it, thus producing what is called a geomagnetic storm. It’s a very good news for aurora hunterssince these events tend to drastically increase the intensity of these superb light phenomena.
and some disruptions to the program
But the same cannot be said for communication systems. Indeed, the local ionization of the atmosphere associated with the impact of the CME can have a significant impact on the propagation of radio waves, which can lead to a blackout in the affected area.
This is also problematic for satellite operators. Indeed, electronic components do not generally get along well with these charged particles. Most devices are protected by the magnetosphere, and therefore do not run any major risk. But the satellites are significantly more exposedsince they evolve at an altitude where the intensity of this protective magnetic field is lower.
Still early days following the X9 solar flare from sunspot region 3842 which is the strongest solar flare of Solar Cycle 25 thus far but we do have some preliminary SOHO/LASCO coronagraph imagery from SEEDs right now. We see the beginning of a very nice halo coronal mass ejection… pic.twitter.com/tJsr6Tk6es
— SpaceWeatherLive (@_SpaceWeather_) October 3, 2024
In addition to the risks for on-board electronics, the impact of a CME can also significantly heat the ionosphere and thermosphere, which has the effect of increasing the volume of the densest gases. And this is very annoying for satellites positioned in relatively low orbits. This expansion can increase their friction with the atmosphere, leading to a gradual loss of altitude that forces operators to react. This summer, a powerful solar flare gave rise to the largest satellite migration in history. Suffice to say that operators will be on alert as these new CMEs approach.
According to NASA models, the first should have hit Earth today, and does not seem to have had any dramatic consequences for the moment; so there is almost no chance of it doing any damage before completely fading. But the second coronal mass ejection, the one associated with this famous X9 class eruption, is expected on October 6. The worst could therefore still be to come.
No solar apocalypse expected
However, there is no no reason to give in to catastrophism. A possible radio blackout should fade fairly quickly, and industries that depend on this mode of communication have procedures in place to limit the impact of these disruptions on their activities. The chances of a plane crashing due to a CME, for example, are almost negligible.
In addition, even if this solar flare is indeed very intense, it is still not powerful enough to cause major damage to electronic equipment on the surface. To get there, it would take an X10+ class eruption, like the famous Carrington Event of 1859 — the largest solar flare ever documented (see our article below).
Source: www.journaldugeek.com
