Some of the biggest mysteries in modern astronomy involve the emission of neutrinos, including high-energy astrophysical events like supernovae and black hole formation that also emit high-energy light in the form of gamma rays. These neutrinos are subatomic particles that interact very weakly with their surroundings, so they can only be observed using very sensitive telescopes, complicating the process to observe them.
To further the studies of extreme phenomena like black holes, rapidly-rotating neutron stars called pulsars, and galaxy merger events, where two galaxies collide, scientists in Russia recently launched a new neutrino telescope into the depths of the world’s largest natural lake: Lake Baikal.
Neutrino telescopes are very different from other types of telescopes in that they must be submerged in water or ice. We can’t detect neutrinos in air because neutrinos rarely interact with their environments, unlike the electrons that produce emissions on the electromagnetic spectrum, ranging from visible light to gamma rays. Instead, neutrino telescopes detect very faint traces of Cherenkov radiation, a different kind of emission, as neutrinos pass through different mediums, usually water here on Earth.
Since neutrino telescopes can only detect traces of Cherenkov radiation through water, the depth and size of the water they are submerged in determines the size of their detection area. Thus, the new Russian telescope will have the largest detecting area of any neutrino telescope currently on Earth because of the sheer size of Lake Baikal. This is crucial, as super high-energy events such as extreme solar flares and star core collapses have recently been shown to correlate with increases in neutrino emissions, a trend that our current knowledge of neutrino emissions can’t yet explain. We still lack understanding of how exactly neutrinos are produced, so observing more of these emission events is a necessary step in understanding what happens in these high-energy events.
Neutrinos are also a candidate for dark matter, an unknown form of matter that can’t be seen, but rather is observed through its effects on the gravitational forces in large systems like galaxies. These particles fall into a category called WIMPS, or Weakly Interacting Massive Particles. While neutrinos by themselves are quite light, as they are subatomic particles, together they are thought to comprise a significant portion of the unknown dark matter mass in the universe. Since we don’t know the specific processes of neutrino emission, it is nearly impossible to make an estimate of the population of neutrinos in our universe. Because of this, we have no way to tell if neutrinos actually do make up a significant enough amount of matter to be considered a similarly significant portion of dark matter until we understand how frequently these neutrino emission events happen.
This new neutrino telescope could hold the key to unraveling the mysteries behind neutrino emissions, especially given its large detecting area. Once we are able to study neutrino emissions more thoroughly with the new telescope, we can narrow down the current dark matter candidates and expand our knowledge of extreme physics.
This article was edited by Joe Ding and Sam Tan.