Russian scientists have deployed one of the largest underwater space telescopes in the southern part of Lake Baikal in Siberia. The telescope, called Baikal-GVD (Baikal- Gigaton Volume Detector), is designed to detect high-energy cosmic neutrinos and search for their sources.
Neutrinos are tiny subatomic particles very similar to electrons but with no charge and almost negligible mass. They are everywhere, but their weak interaction with the forces around them makes it very difficult to detect them.
So typically neutrino detectors are built underwater to shield them for cosmic rays and other sources of interaction. Lake Baikal, being the deepest lake (1,700m deep), and having clear, freshwater and thick protective ice cover, serves as the ideal location to search for neutrinos.
The telescope is submerged to a depth of 750-1300 metres, around 4km from the shore. The floating observatory consists of strings with spherical glass and stainless steel modules attached to it.
The spherical glass has photomultiplier tubes which detect a specific kind of light every time a neutrino passes through a clear medium, like freshwater, at a speed faster than the speed of light in that medium. This light is called Cherenkov light in honour of its discoverer, physicist Pavel Cherenkov.
Researchers say that this telescope will also be used to look for dark matter and other exotic particles.
Baikal-GVD is the largest neutrino observatory in the Northern Hemisphere and is one of the 3 largest in the whole world along with IceCube at the South Pole and ANTARES in the Mediterranean Sea. Currently it is half the size of IceCube but Russian scientists and their collaborators from Czech Republic, Germany, Poland and Slovakia plan to expand it to the size of IceCube in the upcoming years.