An observatory in the Antarctic has spotted ghostly particles from our galaxy and beyond, making researchers confirm the existence of cosmic neutrinos.
Scientists believe that discovering those almost massless particles proves the existence of cosmic neutrinos and could also give them more information about the origins of cosmic rays.
The IceCube Neutrino Observatory has 86 shafts dug into the ice close to the South Pole. The shafts go down 8,000 feet into the ice in order to observe the light from energy particles, using special detectors.
According to specialists, neutrinos are believed to have very little mass and because of that they can easily move through matter. They are believed to originate from sources with high energy like black holes, exploding stars and galactic cores.
Even though neutrinos can’t interact too much with matter, researchers believe that it is possible for neutrinos to hit an atomic nucleus on Earth. That would lead to the neutrinos generating a particle called muon.
Muon is a particle that travels faster than the speed of light even in solid matter. When the muon moves through ice so fast it generates light waves called Cherenkov radiation. The light waves show the neutrinos’ paths.
In 2013, the IceCube project discovered neutrinos that were believed to originate from outside our galaxy. Their origin was not yet proven, so a team of researchers from the University of Wisconsin-Madison decided to investigate whether they were from inside of our galaxy.
In order to determine their origin, scientists analysed neutrinos that had similar energies and came from different directions, but at the same rate. The direction and rate could indicate if they were independent of Earth’s orbit around the Sun and also independent from its rotation.
From 2010 to 2012, the IceCube Neutrino Observatory detected more than 35,000 neutrinos. After analysing them, the scientists found that 20 of them had such high levels of energy that they must have come from cosmic sources.
Those 20 neutrinos came from the opposite direction, but at around the same rate as similar neutrinos observed in the past. Their rate made scientists believe that the place where the observatory was pointing didn’t matter and the rotation and orbit of our planet also seemed to have no impact on the neutrinos’ rate. This made scientists understand that those were actually extragalactic neutrinos.
Physics professor, Albrecht Karle suggests that at least one fraction of the flux had extragalactic origin.
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