Russian physicists are expanding a massive neutrino telescope in Lake Baikal, the deepest and largest freshwater lake in the world. The telescope uses the lake’s ice cover during winter to submerge glass spheres that detect neutrinos by capturing Cherenkov light—blue light emitted when charged particles move through water faster than the speed of light in that medium. This technique allows scientists to observe these elusive particles, which rarely interact with matter and can pass through the Earth with little resistance. Each year, from February to April, the lake’s surface freezes solid, creating a stable platform for operations. Scientists use this time to drill holes through the ice and lower equipment into the water without needing specialized ships or open-water operations. The Baikal-GVD project, launched in 2015, has already deployed 14 clusters, 117 cables, and 4,212 optical modules, creating a detected volume of about 0.7 cubic kilometers. The goal is to reach a full cubic kilometer of detection space, placing it among the world’s leading neutrino observatories. The telescope has already confirmed the existence of a diffuse flux of astrophysical neutrinos—particles originating from cosmic sources such as supernovae or black holes. These findings provide important clues about the origins of these neutrinos, including evidence pointing to a galactic source and new insights into the behavior of a distant blazar known as TXS 0506+056. The optical modules, enclosed in glass spheres, detect the Cherenkov light produced when neutrinos interact with water molecules, creating brief flashes that scientists analyze to reconstruct the neutrino’s path and energy. The Baikal-GVD project has already produced significant scientific results, including an independent confirmation of the diffuse neutrino flux and new information about the galactic origin of the neutrino stream. As the telescope continues to expand, it promises to enhance our understanding of high-energy astrophysical phenomena and the fundamental properties of neutrinos, which remain one of the most mysterious particles in the universe.