IceCube Neutrino Observatory reports first evidence for extraterrestrial high-energy neutrinos

May 16, 2013 by Jill Sakai
The massive IceCube telescope is comprised of more than 5,000 digital optical modules suspended in a cubic kilometer of ice at the South Pole. Credit: IceCube Collaboration/National Science Foundation

( —A massive telescope in the Antarctic ice reports the detection of 28 extremely high-energy neutrinos that might have their origin in cosmic sources. Two of these reached energies greater than 1 petaelectronvolt (PeV), an energy level thousands of times higher than the highest energy neutrino yet produced in a manmade accelerator.

The IceCube , run by an and headquartered at the Wisconsin IceCube Particle Astrophysics Center (WIPAC) at the University of Wisconsin–Madison, identified the neutrinos, which were described today (May 15) in a talk at the IceCube Symposium at UW–Madison.

"We're looking for the first time at high that are not coming from the atmosphere," says Francis Halzen, principal investigator of IceCube and the Hilldale and Gregory Breit Distinguished Professor of Physics at UW–Madison. "This is what we were looking for," he adds. "I would never have imagined that the science would be more exciting than building this instrument."

Because they rarely interact with matter and are unimpeded by gravity, neutrinos can carry information about the workings of the highest-energy and most distant phenomena in the universe. Though billions of neutrinos pass through the Earth every second, the vast majority originate either in the sun or in the Earth's atmosphere. Far rarer are high-energy neutrinos that may hail from the most powerful —such as gamma ray bursts, , or star formation—where they would be created in association with high-energy cosmic rays that can reach energies up to thousands of PeVs.

In his talk, postdoctoral fellow Nathan Whitehorn described 28 high-energy neutrino events captured by the detector between May 2010 and May 2012. These events, including two that exceeded the unprecedented energy level of 1 PeV, were one of the main goals for building a detector such as IceCube.

"Their properties are strongly inconsistent with what you would expect of atmospheric sources and are almost exactly what you would expect from an astrophysical source," Whitehorn says.

It is premature to speculate where these neutrinos originated, he adds, but the IceCube collaboration is continuing to refine and expand the analysis.

IceCube is comprised of more than 5,000 digital optical modules suspended in a cubic kilometer of ice at the South Pole. The National Science Foundation-supported observatory detects neutrinos through the tiny flashes of blue light produced when a neutrino interacts with a water molecule in the ice.

The first hints of high-energy neutrinos came with the unexpected discovery in April 2012 of two detector events above 1 PeV. An analysis of those events was reported last month in a paper submitted to the journal Physical Review Letters. An intensified search, led by Whitehorn and fellow WIPAC scientists Claudio Kopper and Naoko Kurahashi Neilson, turned up 26 additional events exceeding 30 teraelectronvolts (TeV; one-thousandth of a PeV), which will be described in a forthcoming publication.

Explore further: Researchers at IceCube detect record energy neutrinos

Related Stories

Researchers at IceCube detect record energy neutrinos

April 26, 2013

( —Researchers at the Antarctic research station IceCube are reporting that they've detected the highest ever energy neutrinos ever observed. In their paper they've uploaded to the preprint server arXiv, the team ...

Neutrinos put cosmic ray theory on ice

April 20, 2012

( -- A telescope buried beneath the South Pole has failed to find any neutrinos accompanying exploding fireballs in space, undermining a leading theory of how cosmic rays are born.

IceCube neutrino observatory nears completion

August 31, 2010

In December 2010, IceCube -- the world's first kilometer-scale neutrino observatory, which is located beneath the Antarctic ice -- will finally be completed after two decades of planning. In an article in the AIP's Review ...

IceCube researchers come up empty on first neutrino test

April 15, 2011

( -- Physicist Nathan Whitehorn and a team of researchers with the IceCube collaboration have failed to come up with evidence to prove that neutrinos come from, or are caused by, gamma ray bursts, (cosmic explosions) ...

Recommended for you

Flexible ferroelectrics bring two material worlds together

January 17, 2017

Until recently, "flexible ferroelectrics" could have been thought of as the same type of oxymoronic phrase. However, thanks to a new discovery by the U.S. Department of Energy's (DOE) Argonne National Laboratory in collaboration ...

First-ever X-ray image capture of material defect process

January 17, 2017

From blacksmiths forging iron to artisans blowing glass, humans have for centuries been changing the properties of materials to build better tools – from iron horseshoes and swords to glass jars and medicine vials.

Theory lends transparency to how glass breaks

January 16, 2017

Over time, when a metallic glass is put under stress, its atoms will shift, slide and ultimately form bands that leave the material more prone to breaking. Rice University scientists have developed new computational methods ...

A novel way to put flame retardant in a lithium ion battery

January 16, 2017

(—A team of researchers at Stanford University has found a novel way to introduce flame retardant into a lithium ion battery to prevent fires from occurring. In their paper published in the journal Science Advances, ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1.7 / 5 (6) May 17, 2013
G00gle is actively working on the Macroscope, Piers Anthony's 'Super Dooper Pooper Scooper, after realizing that his 'macrons' were neutrinos.

The renewed interest in all things "IQ" are the traces of the search for an IVO Archer-Schon after the breakup of the Peckham Experiment. A good measure of IQ is the foresight to hide ones brilliance under a bushel basket. Ivo was a good lesson for all of us.

Safety is the new Liberty, recklessness is the new Freedom, and Anony Mouse is the new John Handcock.
2.1 / 5 (14) May 17, 2013
Xanth is Florida, the Land of Oz is Down Under, and Metropolis is New York. Also, Starfleet Command is at Fort Baker.

Who knew a warp-field could be generated by a fusion powerplant, or that neutrinos created by that plant could be used for interstellar communications?
May 20, 2013
This comment has been removed by a moderator.
3 / 5 (8) May 20, 2013
Mohammad Shafiq Khan:

But what if you are wrong?
not rated yet May 20, 2013
It isn't hard to infer the existence of high-energy neutrinos in other planetary atmospheres. So 'extraterrestrial' is a bit misleading, as if Earth was the only place high energy neutrinos were found.
2.6 / 5 (5) May 20, 2013
The adopted paradigm of physics has been openly challenged which could be seen at;tab=2
Einstein's space-time concept has been mathematically, theoretically & experimentally proved baseless and General Theory of Relativity & Black Hole concept also have been proved baseless by Stephen Crothers in the published articles in��� peer-reviewed journal-Refer Stephen Crothers web-site. Main-stream physicists are befooling the ignorant people.

Tis a true thing ya say there, but ya forgot to point out that Cothers' peers are other cranks.,,,,

Stephen Crothers was booted out his graduate program because he was disruptive to his classmates, and put great effort into attempting to sabotage the work & research of his professors & supervisors. He was given the golden opportunity to study under one of the truly great astrophysicists of the 20th century, Paul Davies, and threw it away.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.