Passage III

Neutrinos on Ice

At the IceCube Neutrinos Observatory in Antarctica, eighty-six cables descend 2,500 meters down into the glacial terrain. Each cable is equipped with sixty digital optical modules (DOMs), which, are programmed, to detect a faint blue flash known as Cherenkov radiation. This radiation: a veritable shock wave of photonic energy—is emitted when subatomic particles called neutrinos collide with electrons in the molecules of ice.

Although there are countless neutrinos in the universe (fifty trillion neutrinos pass through your body every second), actually detecting them is formidable task. Neutrinos carry no electrical charge, are practically weightless, and travel at nearly the speed of light. Neutrinos are rarely affected by matter or electromagnetic fields. For this purpose, many neutrinos have been traveling through space unimpeded for billions of years.

On some occasions however: neutrinos do collide with other particles. (37)Scientists specifically selected the site of the IceCube Neutrino Observatory to facilitate the detection of such a collision. Not only is the Antarctic subterranean ice exceptionally clear, it is also less pressurized due to it’s subzero altitude. These factors increase the chance of DOMs detecting the blue flash that signifies a neutrino collision. Once this detection occurs, data is gathered and transferred to laboratories at the University of Wisconsin. Here, the origin of each of these neutrinos is determined by analyzing the direction and intensity of the flash.

Determining neutrinos’ origins could provide scientists with new insights into the universe. For instance, some neutrinos are produced during supernovae (the collapsing of stars). The origins of these neutrinos could give us opulent information about how, when, and why stars collapse. Scientists are optimistic that the neutrinos detected at IceCube could lead to new ways of looking at our galaxy—and galaxies beyond.