Recent nights have been a truly remarkable experience, with beautiful auroras visible in the sky. They are visible from virtually all of Poland and even southern Europe. Of course, they were also detected by the ALPS (All-Sky Light Pollution Survey) stations, including the one located in Piwnice, at the Institute of Astronomy of the Nicolaus Copernicus University (IA NCU).
The aurora (borealis and australis) phenomenon appears in the sky as a result of the interaction of highly charged particles from the solar wind (mainly electrons and protons) with atoms and molecules in the Earth's atmosphere. This is related to solar activity – the greater the solar activity, the easier it is to observe the aurora, even far from the Earth poles. When the solar wind reaches Earth, our planet's magnetic field directs it towards the polar regions, where the particles in the Earth's atmosphere ionize. When the atoms of these gases return to their ground state, they emit light of characteristic colors, creating a magnificent show. The color of the aurora is determined by both the type of gas and the altitude at which the phenomenon occurs – oxygen emits green and red light, while nitrogen produces shades of pink.
Last year, there were many opportunities to observe the aurora borealis in Toruń and the rest of Poland, as the Sun has been very active in recent months. We had numerous solar flares and releases of coronal mass ejections, i.e. streams of material emitted from the surface of our star. Upon reaching Earth, these matter trigger magnetic storms and "force" the main components of Earth's atmosphere, nitrogen and oxygen, to emit light - commented dr. Paweł Zieliński from IA NCU. However, the aurora that appeared on the night of January 19th to 20th was exceptional because it was associated with a very powerful solar flare that was oriented directly to the Earth. As a result, experts expected a strong geomagnetic storm, but what we observed seems to have exceeded expectations. The last storm of this magnitude that was registered in Poland occurred approximately 23 years ago.
Agnieszka Gurgul, PhD student and employee of IA NCU adds:
The red aurora is most often seen from Poland, as it is created very high in the atmosphere (200 - 400 km above the Earth's surface) as a result of light emitted by oxygen. Because it occurs at a high altitude, it is visible from a greater distance from the North Pole. This time, however, the effect of the solar wind on our atmosphere was so significant that it was easy to admire the green aurora, which is also associated with ionized oxygen but arises lower in the atmosphere (100 - 150 km), and usually requires being closer to the North Pole, for example, in Scandinavian countries, to detect it. It is often faint and easily lost in the glow of city lights. Moreover, we were also lucky recently, as the nights around Toruń were cloudless.
We invite you to regularly visit the ALPS station website in Piwnice! https://alps.uwr.edu.pl/alps_piw/.
The main goal of all ALPS stations is to monitor the local sky to estimate the degree of artificial light pollution. However, they can also detect various phenomena, from the passage of space satellites in Earth orbit and fuel drops from the Falcon rocket (https://portal.umk.pl/pl/article/spiralny-wzor-na-nocnym-niebie) to the natural and magnificent auroras and meteor and fireball trails. And on a clear night, you can admire the Milky Way - our Galaxy.
You can watch an animation of the entire aurora borealis event recorded in the Piwnice sky on the “Radioteleskop live” website: https://www.facebook.com/reel/803142299453965?locale=pl_PL.
More information about the ALPS project, which includes astronomers from the Nicolaus Copernicus University in Toruń, can be found here: https://www.alps.uwr.edu.pl/.
