ScienceCast: IceCube Project at the South Pole


Uploaded by PennStateScience on 03.06.2011

Transcript:
IceCube, the world's largest-ever observatory to detect sub-atomic neutrino particles, has
been completed in the crystal-clear ice at the South Pole. Trillions of neutrinos stream
through our bodies as they travel through space -- but because they rarely interact
with regular matter, neutrinos have been difficult to study. To unlock some of the neutrino mysteries,
researchers have built the IceCube observatory as an innovative tool for investigating their
properties and their origins, some of which include the most spectacular phenomena in
the universe.
Penn State University scientists have been involved since the beginning of the IceCube
project and Penn State is one of the leading institutions in the IceCube collaboration.
The scientists have made about 20 trips to the South Pole, led by Doug Cowen, a professor
at Penn State, and Tyce DeYoung, an assistant professor at Penn State. To construct IceCube,
the scientists used hot water to melt 86 holes -- each 1.5-miles deep -- into the South Pole
ice cap. They then inserted strings of light sensors into each of the holes. The water
in the holes refroze, locking into the ice a 3-dimensional array of 5,160 light sensors.
These sensors are connected to computers on the surface near the National Science Foundation's
South Pole Station.
The IceCube telescope is designed to detect neutrinos that bombard Earth with energies
far greater than those produced by man-made particle accelerators. These ultra-high-energy
neutrinos may be produced by the super-violent explosions of gamma-ray bursts or by the particle
jets powered by massive black holes. IceCube also may detect lower-energy neutrinos, which
are known to come from the Sun, from cosmic rays, and from other sources.
Neutrinos are uniquely useful to space scientists as probes of the universe because, unlike
light, neutrinos race toward Earth in straight lines from their unimaginably distant birthplaces
unhindered by any matter or radiation that they pass through along the way.
The researchers hope that the neutrinos detected by IceCube will provide the smoking gun that
tells where the cosmic rays that constantly bombard Earth are produced. The IceCube Project
also may provide clues about the nature of dark matter -- the mysterious stuff that makes
up about five times as much of the universe as all the stars, planets, and other normal
matter combined.
For ScienceCast, I'm Katrina Voss.