An observatory situated deep in the Antarctic has spotted some nearly mass-less ghostly particles emerging from the inside of our home galaxy Milky Way and points beyond it. Researchers are saying that this finding other than confirming the existence of neutrinos has also provided us with clues about the source of cosmic rays.
The observatory making the entire event possible is called the IceCube Neutrino Observatory; it’s consists of 86 shafts, which are dug near the South Pole, 8,000 ft into the ice. All shafts have detectors whose primary job is looking for telltale lights emitted by high-energy particles digging through their surrounding ice.
For those who don’t know: neutrinos possess very little mass, as a result of which they zip through matters so swiftly that even a lead block one light-year across will not be able to stop them. Neutrinos emerge from galactic cores, black holes, exploding holes and other such high-energy sources.
Although these particles don’t come in contact with matter frequently, occasionally one may end up hitting one of the earth’s atomic nucleuses. On such occasions, neutrinos give birth to another particle called muon. When looking for neutrinos, scientists usually search for these muons.
When in a solid surface (in this case the solid surface would be ice), muon moves faster even than light and produces light waves. This phenomenon is referred to as Cherenkov radiation. The muons are also known for their ability to show the paths of neutrinos.
In 2013, the IceCube Neutrino Observatory spotted neutrinos emerging from outside our home galaxy. For confirming that detection, the research team representing the University of Wisconsin-Madison had to prove that the neutrinos didn’t have their source within the Milky Way. The researchers searched for neutrinos boasting similar energies and coming from all directions at similar rates. This means they were not affected by factors like the orbit surrounding the sun and the rotation of the Earth. This could happen only if their sources were outside our galaxy.
The researchers were also required to sift out the muons created due to crashing of cosmic rays into a plant’s atmosphere. The scientists working on this project used our home planet Earth for weeding out the majority of those muons by pointing the IceCube Neutrino Observatory through the planet and toward the sky of the Northern Hemisphere.