To study the universe's engimas, researchers plunged the world's largest underwater telescope into the depths of Siberia's Lake Baikal on March 13. The spherical telescope, called the Baikal-Gigaton Volume Detector, is designed to detect and observe the elusive neutrinos, the Agence France-Presse reported.
Neutrinos are the smallest, most abundant particles within the universe and could be the reason matter exists at all. The ghost particles are so plentiful that trillions of them pass through the human body every second. The particles are incredibly hard to capture because they travel almost at the speed of light. Although abundant, neutrinos are not absorbed by matter or deflected by magnetic fields. They only interact with gravity and "weak force," which, in particle physics, is a term used to describe the interaction responsible for subatomic particle decay.
Although similar to electrons, neutrinos do not carry an electric charge and have almost no mass. Because neutrinos are neutral and hardly interact with anything, they are challenging to detect—but not impossible. Areas that are bountiful in water and ice, like lakes and glaciers, are the best places to detect neutrinos. For example, the IceCube Neutrino Observatory is encased in ice in the South Pole and ANTARES is located in Mediterranean Sea off the coast of Toulon, France.
These telescopes detect neutrinos through water Cherenkov experiments. Water acts as a detection medium and increases the chances that a neutrino will interact. When a lightning-fast neutrino hits water, light, or Cherenkov radiation, is emitted. The telescopes have long strings of light-sensing equipment called optic modules placed underneath ice or water that can detect when a neutrino collides with them. The Baikal-GVD telescope has a cluster of eight strings that contain 12 optic modules, and each one is vertically spread out 49 feet from the other. The modules occupy an area of 17,657 cubic feet, reports Igor Bonifacic for Engadget.
The Baikal-GVD was a collaborative effort that began in 2015. The team consisted of researchers from Russia, Czech Republic, Poland, Germany, and Slovakia. In 2015, the telescope had 192 optical modules but has since been updated and now has 288 optical modules. As the largest telescope in the Northern Hemisphere, the research team says it can rival IceCube in the South Pole, reports Fabienne Lang for Interesting Engineering.
Lake Baikal's location and seasonal ice cover lasting two months makes it the perfect area to detect neutrinos, Interesting Engineering reports. The Baikal-GVD telescope is located 2,500 to 4,300 feet deep into the lake.
"Of course, Lake Baikal is the only lake where you can deploy a neutrino telescope because of its depth. Freshwater is also important, water clarity too. And the fact that there is ice cover for two-two and a half months is also very important," said Bair Shoibonov of the Joint Institute for Nuclear Research to the Agence France-Presse.
As fundamental building blocks of the universe, neutrinos can help researchers understand the early stages in the universe's evolution, dark matter, and the evolution of stars. Baikal-GVD's team hopes to use the telescope to study the fluctuation of neutrinos and their sources.