The aurora captured in a mountain village in Italy. The faint light appearing on the far right is presumed to be caused by the SAR arc phenomenon, not the aurora./Courtesy of Alessandra Masi

On the first day of the new year in 2025, a red aurora was captured in Pieve di Cadore, a mountainous city in northern Italy. The aurora in the photo is divided into three zones. The auroras on the left and in the center were created by explosions resulting from increased solar activity. The light that causes auroras is due to strong energy particles falling vertically to the Earth's surface and colliding with the atmosphere. However, the faint light seen on the right is presumed to have been created by particles flowing horizontally with respect to the surface. This phenomenon, known as "SAR arc," occurs due to strong geomagnetic storms.