An award for the study of solar flares

It appears quiet. However, this tranquillity is often deceptive. In reality, it can be quite calm, but when it unleashes its fury, the 150 million kilometres that separate us from the Sun become insignificant. The Sun, which is the source of energy for all human activities and nearly all forms of life on Earth, can also be deadly. To be clear, it does not pose a direct threat to our lives. On the contrary, it creates breathtaking phenomena, such as the polar auroras. Nonetheless, for a complex and vulnerable technological civilisation like ours, the Sun can inflict severe damage on a global scale, particularly through solar flares and coronal mass ejections (CMEs). These topics are discussed in Andrea Francesco Battaglia's doctoral thesis at the Swiss Federal Institute of Technology in Zurich. Battaglia, now a postdoctoral researcher at the Istituto ricerche solari Aldo e Cele Daccò (IRSOL), affiliated with the Università della Svizzera italiana, was recently awarded the Edith Alice Müller Award 2025 by the Swiss Society of Astronomy and Astrophysics for his work.

Flares and CMEs are related but distinct. «A flare is the instantaneous response on the Sun to the violent release of magnetic energy and manifests itself through the emission of intense radiation across the electromagnetic spectrum», explains Battaglia. «A CME, on the other hand, consists of the ejection of solar matter into interplanetary space: plasma, not radiation as in flares». The consequences can also be very different. «A flare emits radiation in all directions, increasing its potential impact, while a CME causes damage only if it is directed towards Earth, although that damage can be much more severe». But what kind of damage are we talking about? «The ultraviolet and X-ray radiation emitted by a flare can damage artificial satellites, disrupt electricity transmission, and endanger the health of aircraft crews and passengers.» A CME, on the other hand, by distorting the Earth's magnetic field and causing induced electric currents to the ground, can cause large-scale blackouts lasting days or even weeks or months. And both together: is that possible? «Although distinct, the two phenomena are related», Battaglia points out. «The more intense the flare, the more likely the CME. So there is a double effect on Earth: ultraviolet and X-ray radiation and, at the same time, the direct impact of plasma». While the electromagnetic radiation from a flare reaches Earth in 8 minutes, the ejected matter takes longer. Therefore, a geomagnetic storm occurs several hours later.

Understanding solar flares and CMEs is essential to improving our forecasting capabilities and ensuring the safety of the technological infrastructure on which our lives now depend. Neither electromagnetic radiation nor solar plasma would directly kill anyone, but many people would die from the indirect consequences, not to mention the disruption we would all face. Among the instruments designed to study flares and CMEs, one of the most advanced is STIX, an X-ray telescope mounted on Solar Orbiter. STIX was designed and assembled in Switzerland at the Fachhochschule Nordwestschweiz (FHNW) in Windisch, which is the institute responsible for operating the instrument and coordinating observations. Solar Orbiter is an ESA mission launched in 2020 and placed in a close orbit around the Sun, so that it is closer to the star than the planet Mercury. The start of Battaglia's PhD coincided with the era of the Solar Orbiter mission. But why this particular research? «The solar physics of flares is the perfect intersection of the topics I am most passionate about: observational astronomy using telescopes on Earth, exploration with space telescopes and high-energy physics», explains Andrea Francesco Battaglia. These are highly topical subjects. «Space weather is becoming increasingly important in the new space age, especially with the growing accessibility to Earth's orbit. Additionally, we aim to return to the Moon, this time with the intention to stay».

Difficult, but not impossible. Let's look to the future: MagnIIFICuS (Mg II pre-Flare Investigation CubeSat). «MagnIIFICuS is an idea developed together with colleagues from the University of Bern and FHN Windisch. We asked ourselves: what instrument would allow us to continue investigating the results we had just obtained? The answer was MagnIIFICuS. Perhaps this is one of the reasons why the thesis won the award, as I did not limit myself to reporting the results obtained during my almost four years of doctoral study, but added a chapter in which I presented the basis for future space missions, including a concept design for MagnIIFICuS». And what is MagnIIFICuS? «It's a CubeSat», explains Battaglia, «i.e. a small satellite designed to be a technology demonstration but also to provide the observations needed to continue investigating microflares through polarisation measurements in ultraviolet rays, which is crucial for reconstructing the magnetic field».

Okay, that's great. But is it realistic? In other words, will MagnIIFICuS actually happen? «We are moving forward with the project», concludes Andrea Francesco Battaglia. «The idea is to publish a scientific article in the near future on an instrument that is the same or similar to MagnIIFICuS, in which we will show the complete design. Given the strong technological demonstration component, the time from design to implementation is expected to be medium to long. The microlenses in the instrument, which have never before been used for solar observations in space, will play a crucial role in ongoing research on solar flares. Various research groups are exploring the application of this technology to answer different scientific questions, and we are establishing our own niche with the design of MagnIIFICuS.».

It appears quiet, we said. But it only appears that way. When the Sun unleashes its fury, it can be deadly. We enjoy its light and warmth, often unaware of the dangers it poses—blissfully ignorant. This is how humans tend to act: we underestimate danger until we come face to face with it. Long before 2020, virologists and epidemiologists warned about the possibility of a global pandemic, but unfortunately, their warnings were not taken seriously. Let's hope we have learned our lesson when it comes to space weather as well.