- Alexandra Martins
- BBC News World
Seeing the image above, the Spanish scientist José Carlos del Toro Iniesta was stunned.
“I am an expert in solar physics, but above all I am a human being and the first thing I feel is what any human being feels, the astonishment of beauty. If something distinguishes us human beings, it is that we know how to distinguish, apprehend and communicate beauty. It is what gives meaning to our lives”.
The image of the colossal ejection of solar material was released this week by the European Space Agency (ESA).
And it was captured on February 15 by one of the instruments of the Solar Orbiter spacecraft, a joint mission of ESA and NASA.
The image captures what is known sunburst eruptionas explained to BBC Mundo Del Toro Iniesta, one of the main researchers of the Solar Orbiter mission and professor at the CSIC (Higher Council for Scientific Research) at the Institute of Astrophysics of Andalusia.
“Solar prominences, not always, but many times, erupt and eject solar material into the interplanetary medium, and eventually that material reaches Earth.”
“They are areas of the Sun in which the material is denser and colder than the surroundings, but remains suspended above the surface by the action of the magnetic field.”
The scientist pointed out that when the magnetic field is reconfigured due to some disturbance, when its topology changes, the energy that was stored in the magnetic field is transformed into kinetic energyof movement of the gas, which is expelled”.
The image captured by Solar Orbiter “is absolutely spectacular because it shows solar material that is literally leaving the Sun at distances of several solar radii while maintaining continuity. In that sense, it is the largest solar flare ever observed.”
It is also an unusual image because the entire disk of the Sun is observed.
“Normally, solar physicists tend to observe small pieces of the Sun in detail, not the entire Sun,” said the expert.
The risks of solar storms
In the case of this ESA image, the ejection of solar material was not directed at Earth. In fact, he was walking away from us.
But what happens when those particles reach Earth?
“This material breaks off from the Sun, travels through the interplanetary medium and reaches Earth, producing the famous solar storms. They should be called geomagnetic storms because it is on Earth where the storm is taking place, even though its origin is solar,” said Del Toro Iniesta.
“Basically, the solar particles are ejected with great energy, at very high speeds, sometimes almost relativistic speeds, a third, a quarter of the speed of light, nonsense. That kinetic energy of the material, when it reaches Earth it finds our protective shield, which is the Earth’s magnetic field“.
“The particles are basically protons, hydrogen atoms from which the electron has been removed. As they are electrically charged, when they reach the geomagnetic field, it forces them to move along the field lines.”
Since the geomagnetic field is born at the North Pole and closes at the South Pole, what the particles do when they reach the geomagnetic field is travel towards the poles.
“When entering closer to the planet through the poles, the first thing that forms are the auroras, which we are used to seeing and is the most beautiful effect of these solar storms. But he’s not the only one”.
Del Toro Iniesta explained that when the particles are especially energetic, then the shock is more pronounced and particles can even overcome the geomagnetic shield and reach parts of the atmosphere closer to Earth, typically the ionospherealtering their chemistry.
“Now in this Zoom conversation we are using the ionosphere because we are communicating by satellite,” explained the Spanish scientist.
“Satellites, radio communications use the ionosphere as a mirror, so, of course, if you alter the ionosphere, you alter communications.”
These disturbances can affect GPS systems, which are used in cars to navigate from one point to another.
If there are changes in the satellite’s orbit “we lose precision, something that in our case may be of little concern. But if the person who is helping the satellites is a ship with thousands of tons of crude oil and a lot of money involved, or a transoceanic passenger aircraft that are the most vulnerable to these particle bombardments because they go through the poles, so this might endanger the lives of the passengers”.
“In fact, the International Space Station has a panic room, a vault with a great thickness of lead, so that when these solar storms occur, the particle bombardment does not affect the astronauts,” added the expert.
Particle bombardment affected large bundles of cables and caused a multi-hour blackout in 1989 across the entire eastern seaboard of Canada and the United States.
“Our life is increasingly dependent on technology and is increasingly vulnerable to this type of phenomenon that has been happening since the Sun is Sun and since the world is a world, that is, 4,500 million years in which history repeats itself. But until now, we weren’t that sensitive to this phenomenon.”
The Solar Orbiter mission will allow scientists unprecedented observations.
The mission “brings together remote-sounding and local-measuring instruments for the first time. Remote-sounding instruments are those in which we are looking at the Sun from the spacecraft at a distance, like the instrument that produced this photo.”
“But then we have local measurement instruments, with which we measure the properties of the particles that we encounter on our journey. Since these particles originate from the Sun, for the first time we have the means to understand the measurements of local particles. and their origin”.
“Besides, we do getting closer to the Sun than anyone has ever done. We are going to zoom in to 0.3 astronomical units (an astronomical unit is the distance between the Earth and the Sun). We are approaching as the orbit of the planet Mercury. We are going to get very close with that battery of instruments and that is going to provide us with information to understand many things”.
Scientists seek to understand, for example, how the Sun generates all the phenomena that later have consequences in the heliosphere, in the interplanetary medium.
“The heliosphere is the small piece of the universe in which the Sun has a noticeable influence. So, understanding the origin and behavior of these phenomena is something fascinating.”
But there is one great mystery in particular.
“There are questions that solar physicists have been crazy regarding for a long time. We know that the part of the Sun where the bulge comes from, the Sun’s corona, is a lot hotter than the surface. A lot.”
“On the surface we have 6.000 degrees and in the crown we have millions of degrees. That’s not normal, because? At home we check it, the hot heats the cold, and the source of heat is in the center of the Sun. If the energy transport were only by radiation, the temperature of the solar material would have to decrease monotonically as we move away from it and that’s what it does up to the surface, but then boom! goes up suddenly. Where does that energy come from?”
“We believe that it is channeled by magnetic fields and other non-thermal processes that transport energy from the inside to the outside, but in a peculiar way. We think that the thing is going that way, but we do not yet have reliable evidence.”
“And like that there are many other questions.”
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