Satellites fall and radio outages in two continents... What is happening to the sun these days?

Perhaps you have heard somewhat strange news about the sun during the past few weeks. One of them (1), for example, says that 17 consecutive solar eruptions occurred recently in sunspot number 2975. Two of these eruptions were towards the Earth, which heralds the coming of a strong geomagnetic storm coming within days. With warnings of various technical problems.

That was on the 30th of last March, and the matter did not calm down until it was announced on the 11th of April (2) that another sunspot had exploded, which led to a massive ejection of solar material heading towards the Earth.

This time, spot number 2987, expelled exploding balls of solar material, actually reached our home planet on April 14.

As for the last news, it appeared on April 25, when the “SpaceWare” platform (3) announced that a massive solar disturbance had caused a number of interruptions in radio communications in the continents of Asia and Australia, which sparked fear from successive news about the raging solar activity these days. and its impact on human life.

This time around, it was sunspot number 2993, which experienced a medium-sized explosion, but it was so impressive.

A picture of the sun taken by the author of the report on the morning of April 26. Take a look at the three spots above, the largest of them being spot No. 2993, which caused the radio outages.

And you may remember that on February 8, the company (4) “SpaceX” announced that more than 40 satellites of the “Starlink” project had fallen from its orbit into space to Earth, only 5 days after its launch, due to A powerful geomagnetic storm was associated with a massive explosion on the surface of the Sun that released about one billion tons of charged particles into space towards Earth.

What happens to the sun?

Well, to understand it let's start from scratch.

On the surface of the sun, the temperature is about 6000 degrees Celsius, and inside it reaches 27 million degrees.

Because of this intense heat, the sun is formed from "plasma", which is a form of matter in which electrons are stripped from atoms and floats freely.

This plasma has very special characteristics, the most important of which is its wide ability to conduct electricity, produce magnetic fields and interact with them easily.

One of the shapes that plasma takes on the surface of the Sun are the massive, captivating "solar prominence" rings, so huge that one can fit more than three Earths-sized balls.

To understand how these rings are formed, let's give an example.

During boiling, the internal parts of the water are hotter than the surface, and "hottest" means "less dense", so it rises to the top, and in return the cold parts of the water descends to the bottom, becoming hotter while the parts that rose a little while ago cool down, so the same process is repeated again.

In the sun, something similar happens. The plasma moves between the upper layers of the star in a continuous movement. When the plasma streams rise to the top, they cool down, becoming heavier than the lower currents, and thus return again to the bottom and rise in their place of hotter currents, and so on.

Note the massive solar flare

Each stream of plasma traveling between the upper layers of the sun is like a magnet with a north pole and a south pole, with magnetic rings between them.

To approximate it, you might consider the iron filings rings that are created when a magnet is placed on a sheet of white paper.

But what happens sometimes is that some of these rings get tangled together, and are strong enough to prevent the plasma from going down as usual, so the plasma will cool compared to the surrounding sun surface creating what we call 5 “sun spots”, which are areas with temperatures lower than The rest of the surface of the sun, and although these areas remain very hot, the difference in radiation between them and their surroundings causes those spots to appear completely dark to our eyes or to the cameras that take their pictures.

Solar flares only occur in those active regions on the surface of the Sun that contain sunspots.

Sometimes one of these rings of a solar flare can explode, releasing a huge amount of energy and matter into space at very high speeds. This is called a "solar flare", which is what we just talked about.

A solar eruption is like squeezing a spring with great force and then suddenly letting it go, as huge rings of plasma trap a great deal of energy and are suddenly released into space, traveling to Earth and other planets.

Other times, the solar eruption is much more powerful than common eruptions and is called a "coronal mass ejection," which actually happened on April 11.

Despite the differences between the two cases, each of them makes what we know as the “solar wind”, which is a figurative term that expresses those quantities of matter and energy that emanate from the sun, reach the planets of the solar system and interact with their magnetic poles to make one of the most beautiful phenomena that can be To see it, the aurora borealis.

It is worth noting that when the solar wind causes a great disturbance to the Earth's magnetosphere, we call it a "geomagnetic storm".

aurora borealis

Is this solar activity normal?

At that point, let's get acquainted with the "solar cycle", which is the change of solar activity with time, as it starts weak, then rises little by little until it reaches its top, then decreases again until it reaches the bottom, and so on (6) .

Scientists know about this cycle by following the spots on the surface of the sun, when the sunspots are many and close to the poles, this means a great solar activity (Solar Maxima), but when it is few and close to the middle, this means weak solar activity (Solar Minima), the duration of the solar cycle She is 11 years old, and we do not yet know the reason for that cycle, and why it occurred in that particular period.

Right of the image: aphelion of solar activity - left: perihelion of solar activity.

The lowest solar activity reached by the sun in the current cycle (the 25th cycle in the measurement date) was in December 2019, after that the solar activity increased little by little and we are now heading to the maximum solar activity, which is scheduled sometime around July 2025, This is all normal and happens every 11 years, but there is an important note in the current cycle.

The previous solar cycle was fairly quiet, with the number of sunspots at its peak reaching 114, while the average in this case is 179. Scientists (7) predicted that the current cycle would be similarly quiet with 115 sunspots at its peak, but it seems That does not happen, we are still not even close to the peak of the current solar cycle and the number of sunspots has crossed the 61 barrier.

So far, the reason for this is not understood.

Is there a danger to our lives from this mess?

What is certain, then, is that you will hear about a lot of solar explosions and geomagnetic storms from now and for the next several years, and you will see a wonderful group of images of the aurora borealis, but you must now wonder about the impact of all this on our safety, and the safety of our Earth.

Generally, this type of solar activity is safe for human health, but there can be serious technical damages, for example, according to one study (8), a strong geomagnetic storm may destroy more than 300 transformers and leave more than 130 million people without electricity. In the United States of America, at a cost of several trillion dollars.

This happened before, for example, a strong geomagnetic storm had erupted from the sun towards the Earth in March 1989, causing a complete blackout in the Canadian Hydro-Quebec system (9) for the distribution of electricity, for a full nine hours.

The same thing happened in August of the same year in Toronto, and it was all during the peak of solar activity of the 22nd cycle.

On the other hand, these solar explosions can affect the communications systems, satellites and navigation that depend on them, and what happened to the Starlink satellites is a good example, as well as the bodies of astronauts can be affected when they are exposed to radiation from those high-energy solar particles, in the long run.

As for the most dangerous scenario in this regard, an international research team pointed out in a study published in (10) “Astrophysical Journal” in June 2019. The study indicated that there is a type of superflares that is likely to occur on the surface of the sun every Several centuries, usually thousands of times more powerful than typical solar flares.

The research team believes that this type of solar explosion may hit the Earth with an unimaginable amount of energy-charged particles, which may hinder wireless communications and disrupt satellites and enter the Earth in a wave of complete darkness, because it may cause the disruption of power stations and electronic devices in general, which It could turn the Earth back a thousand years.

___________________________________________________

sources: