One of the coolest labs on Earth, the IceCube Neutrino Observatory, had some pretty hot news to report last week: evidence for very high-energy neutrinos arriving from outside our solar system.
Neutrinos are like lonesome cosmic wanderers – the nearly massless subatomic particles travel rapidly through space and interact with little. As you read this, billions of neutrinos are streaming through you, but you would never know it.
IceCube was set up to capture the calling cards of high-energy neutrinos from violent astrophysical sources, such as exploding stars and gamma ray bursts. It uses more than 5,000 “digital optical modules” embedded in a cubic kilometre of Antarctic ice, where the high pressure and lack of light offer a relatively friendly environment for detecting the ethereal speedsters. When a neutrino interacts with ice, there’s a tiny flash of blue light, and the detectors are there to register the happy occasion.
Last week a paper in the journal Science described 28 very high-energy particle events in data collected in IceCube over the course of about two years.
"It is gratifying to finally see what we have been looking for," said Francis Halzen, principal investigator of IceCube and the Hilldale and Gregory Breit Distinguished Professor of Physics at the University of Wisconsin-Madison. "This is the dawn of a new age of astronomy."
