UH Manoa-led research team successfully completes first long duration balloon flight around Antarctica in search of neutrinos

NASA-sponsored flight is second longest on record at 35 days; five-year project aims to detect high-energy neutrinos within the Antarctic ice sheet

University of Hawaiʻi at Mānoa

HONOLULU — A research team led by the University of Hawaiʻi at Mānoa is celebrating the successful completion of a recent 35-day, stratospheric balloon flight around Antarctica carrying a detector they built to find the elusive neutrino, a particle that could unlock the secrets of the universe. Detailed results from the flight will not be known for months, but the flight itself has been deemed a tremendous success for the research team and the National Aeronautics and Space Administration (NASA), who initially selected the project as part of its 2002 Space Science Research Program and awarded UH Mānoa a five-year, $8.5 million grant to support it.

The Antarctic Impulsive Transient Antenna (ANITA) project, led by principal investigator and UH Mānoa professor Peter Gorham, is the first neutrino observatory of any kind ever supported by NASA and its 35-day flight that launched on December 15, 2006, is the second longest on record for any scientific balloon flight ever.

"Astrophysicists have recognized for some time that neutrino observations are crucial to our understanding of the most energetic objects in the universe," says Gorham. "Neutrinos are really at the frontier of our understanding of particle physics, almost mystical in their properties, almost otherworldly. So it‘s kind of fitting that the last frontier on earth—Antarctica—turns out to be one of the best places to go and search for them."

ANITA, a project which involves eight other universities and NASA‘s Jet Propulsion Laboratory, is designed to view the Antarctic ice sheet from horizon to horizon using a sophisticated array of antennas (as seen in photo at right) to "listen" for sharp bursts of radio waves emitted by cosmic high energy neutrinos as they interact deep within the ice sheet, producing what amounts to a mini bolt of lightning in the ice sheet. The payload of microwave antennas is carried around the Antarctic ice sheet by a stadium-sized balloon circling at an altitude of 120,000 feet—four times as high as a passenger airplane travels.

Antarctica was selected as the best site because its ice is completely transparent to radio waves and because it is one of the most radio-quiet spots on Earth. Thus, at the altitudes of 120,000 feet attained by NASA high-altitude balloons, ANITA can simultaneously monitor over a million cubic kilometers of ice, turning the entire Antarctic continent into an enormous neutrino telescope.

Neutrinos are subatomic particles, the smallest building blocks of all matter, which interact so rarely with other matter that one could pass untouched through a wall of lead stretching from the Earth to the moon. Scientists are still puzzled as to where they come from, and figuring this out could lead to a better understanding of the Big Bang theory and the origins of the universe.

The team will propose up to two additional flights for December 2008 and December 2010. Initial release of results from data collected this year should occur by late summer.

In addition to NASA‘s Jet Propulsion Laboratory, other universities participating in the ANITA project led by UH Mānoa include University of California, Irvine; University of California, Los Angeles; Ohio State University; University of Delaware; University of Kansas; University of Minnesota; Washington University, St.Louis; and the Stanford Linear Accelerator Center, operated by Stanford University for the U.S. Department of Energy.

For more information about the ANITA project, visit www.phys.hawaii.edu/~anita/web/index.htm.

For more information, visit: http://www.phys.hawaii.edu/~anita/web/index.htm