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The Honolulu Advertiser
Posted on: Wednesday, November 5, 2003

UH gets $35 million to join hunt for elusive neutrino

By Beverly Creamer
Advertiser Education Writer

The University of Hawai'i has landed a $35 million, five-year grant from NASA to capture ultra-high frequency neutrinos in the Antarctic ice sheet with the hope of better understanding the origins of the universe.

It's the largest single grant awarded to the Department of Physics and Astronomy — and likely the largest ever won by the university as a whole.

UH President Evan Dobelle said it's proof that UH scientists are on the "cutting edge" of neutrino research. And grant principal investigator Professor Peter Gorham said it shows that by fast-tracking the UH program NASA "is willing to forge ahead in a very new direction.

"As far as I know NASA has never done anything in the realm of high-energy neutrino astronomy," said Gorham. "This is a project that is really pushing out beyond the limits of anything we've done before.

"It's very exciting for UH because it shows that NASA is willing to consider proposals from institutions they haven't traditionally supported at this level."

Neutrinos are the smallest building blocks of all matter, but it's still a mystery where they come from. They could originate in massive black holes in the center of galaxies. They could be traveling from the farthest reaches of the universe, said Gorham, but our understanding of them is still in its infancy.

With neutrinos still a puzzle to scientists, it's only in the past couple of years that there's been understanding that they have mass.

"We have as many as 100 models of where these particles might come from," said UH professor John Learned, a neutrinos expert. "But they're all strange and there's no simple solution. They may be decay from the Big Bang, they may have to do with black holes. We really don't know where these guys are coming from."

So figuring out their origin will mean science can begin to better explain the Big Bang theory and the excess matter left over that became life.

Gorham's ANITA project — Antarctic Impulsive Transient Antenna — which won the grant, is one of five chosen for financing by NASA's 2004 Explorer Program Missions.

The project involves sending a balloon the size of the Rose Bowl 25 miles above the Antarctic ice-cap carrying a payload of sophisticated microwave antennas. This array of antennas will be aimed at the Antarctic ice sheet from horizon to horizon to "listen" for sharp bursts of radio waves emitted by high-energy neutrinos as they enter the ice cap.

In effect, the entire Antarctic continent becomes an enormous telescope lens.

Neutrinos can penetrate the depths of space, but are very difficult to detect as they go through rock, lead, the earth itself. But when they interact with ice they create a detectable radio wave.

"They make a mini-bolt of lightning in the ice and this radiates a very characteristic pulse," said Learned. "As it turns out, the ice is extremely transparent to radio waves."

The payload carried aloft by the balloon for anywhere from 15 to 30 days will record the action produced by the neutrinos so that scientists may begin gauging their origin.

"We may for the first time observe particles from the far reaches of the universe that have energies a billion times higher than we can produce on earth," said Gorham, whose team will be working much of the time at NASA's Jet Propulsion Laboratory that's part of the California Institute of Technology.

ANITA is the first long-duration balloon project ever selected as part of the Explorer program. UH research and development for it began earlier this year with an $8.2 million grant from NASA space research and technology.

"If ANITA were to see the first glimpses of very high-energy neutrinos from distant galaxies, it would give a huge thrust to the idea that we can do a totally new kind of astronomy with unheard of telescopes," said Gorham.

"We could use planet-size volumes of material as our particle detectors. It will open up a window to the universe that so far we've only had glimpses through."

At this point the long-term impact of neutrino astronomy can only be imagined, but Learned sees exploration now as the first baby steps toward learning to harness the particles.

"There are spin-offs that we can't foresee," said Learned. "When the electron was first discovered a century ago someone asked 'What good is it?' and the answer was, 'It's no good at all, sir.'"

UH scientists also played a key role in the analysis and discovery of neutrino oscillations and hence neutrino mass, in the Super-Kamiokande detector in Japan in 1998, a discovery that received international coverage and is now heralded as the most important of the 1990s in elementary particle physics.

Reach Beverly Creamer at bcreamer@honoluluadvertiser.com or 525-8013.