“Solar Orbit”: towards the sun with technology from Austria

It is difficult to overestimate how important the Sun is to the Earth. Not only does our planet exist thanks to the fixed star, but life on Earth is also unthinkable without the Sun – at least in its current form.

It is therefore understandable that the Sun has always aroused people's curiosity and has long been the focus of scientific research efforts. Accordingly, we already know a lot about our parent star – we know the size, temperature and age of the Sun and we understand the thermonuclear processes that generate energy in its core. However, the sun still mystifies science.

Extreme weather conditions

These are constantly created around the Sun Solar windThrough which charged particles from the sun flow in all directions. However, this stream of particles does not always “explode” with the same force: at times when the Sun is particularly active, it sweeps into space with greater force – with consequences that people in Austria were also able to observe a few months ago. Strong solar winds were responsible for the northern lights suddenly appearing in the night sky in May.

The weather around the Sun can also be more extreme: driven by the stationary star's dynamic magnetic field, larger bursts of radiation occur, called Torches. If these forces are particularly strong, parts of the solar magnetic field could become isolated and pull large amounts of solar plasma into space. The solar wind is particularly strong at that time.

“We understand a lot of fundamental processes, we understand how the Sun produces its energy, and we also understand in principle how it generates its magnetic field, which can then lead to these radiation explosions,” explains the astrophysicist. “But we still have a relatively imprecise understanding of the timing of The occurrence of such explosions and the accuracy of the processes that occur in them. Astrid Veronig from the University of Graz told science.ORF.at.

Danger from space

Such mass explosions, also known as solar storms, sometimes pose a danger to people on Earth: “First of all, the infrastructure in space is directly at the mercy of the solar storm, that is, the satellites,” explains Veronig. It has happened several times in the past that a solar storm has crippled the technical equipment of a satellite or rendered it completely unusable. “This could even change the satellite’s orbit and thus burn it up in the Earth’s atmosphere.”

Since many systems on Earth rely on satellite data, this can cause problems. But a particularly strong solar storm could cause more damage. “If the magnetic field carried by the solar storm merges with the Earth's magnetic field, the Earth's magnetic field may weaken for a few hours to days. On the one hand, this allows high-energy particles to penetrate the atmosphere, but on the other hand, the fluctuating magnetic field also creates strong currents In the ground and in the cables.

The latter poses a particular risk to the power grid and IT infrastructure on Earth. “This could lead, for example, to regional power outages,” says the astrophysicist, who also says that it cannot be completely ruled out that a very strong solar storm could lead to widespread power outages at some point.

Good conditions

A better understanding of solar storms not only benefits basic research, but also helps understand the conditions under which storms arise in space.

Veronig and her team also want to find out, and now is a good time to do so because the Sun is currently more active than it has been in 20 years. “They show a lot of very large radiation bursts as well as solar storms. And of course, it is always useful for science that we can study many of these epidemics in order to deepen our knowledge.”

Data from near the sun

Researchers rely on data coming from the Solar Orbiter space probe. The European Space Agency (ESA) probe has been moving since 2020, orbiting the Sun in highly elliptical orbits and occasionally flying close to the Sun. There are a total of ten scientific instruments on board that focus on the sun, and they are well protected behind a heat shield.

Behind one of the observation windows is STIX, an X-ray telescope in which Veronig is also heavily involved. “The X-ray telescope can image the interactions of these high-energy particles with the Sun's surface very well. This means that we have measurements here that allow us to know where the accelerated particles are hitting the Sun's surface, how many there are, how they are distributed and what the acceleration timing of these particles is.”

“Solar Orbiter” before an exciting section

Veronig expects more important data from Solar Orbiter in the near future, as an exciting mission phase begins for the space probe: as part of several flight maneuvers on Venus, it collects energy, which it then uses. Ecliptic It will run out. This is an imaginary plane around which almost all the planets in the solar system revolve.

With the departure of this plane, Solar Orbiter will be able to examine the poles of the sun in about two years. “Until now we can barely observe the Sun's poles – but they are very important for understanding how the Sun's magnetic field evolves. Here, the Solar Orbiter will certainly make important contributions,” explains Veronig.

Experts expect future observations to provide more insights into the Sun's complex magnetic field and the formation of solar storms. Will this finally make it possible to better predict solar storms that cause problems on Earth? “This is of course a key goal in almost every solar physics mission. However, at present, we still lack some fundamental knowledge so that significant improvements in these predictions can eventually be achieved.”