Photos: Huge Observatory 1.5 Miles Deep in Antarctic Ice

Finishing Touches
Photograph courtesy J. Haugen, NSF
Drill manager Dennis Duling signs a particle-detecting sensor, part of the newly completed IceCube Neutrino Observatory, in Antarctica in December 2010.
Situated at the geographic South Pole, the U.S. $279 million observatory—the largest of its kind—will search for neutrinos, mysterious subatomic particles that can travel through almost any type of matter.
Neutrinos are born of some the universe's most violent events, such as star explosions, gamma ray bursts, and cataclysmic phenomena involving black holes and neutron stars, according to the IceCube website.
Echoing some undersea neutrino observatories, IceCube is made of up 86 sensor-equipped cables that snake down ice holes as deep as 1.5 miles (2.5 kilometers). The cables are linked to a surface laboratory.
(Related: "Particles Larger Than Galaxies Fill the Universe?")
"The advantage of ice is that you can walk on your experiment," said Francis Halzen, a physicist at the University of Wisconsin at Madison and principal investigator for the IceCube project, which is funded by the U.S. National Science Foundation (NSF).
Because the detectors will be frozen into the ice, scientists were able to place the surface-based data-acquisition electronics and computers right on top of the detector, Halzen said. In water, it's more difficult: Equipment must be more sophisticated and continuously fight a hostile environment of deep ocean water, for instance.
For IceCube, "all we do is build a sensor, freeze them in, and [the sensors] live forever. It did turn out to be simple."
—Christine Dell'Amore, with reporting by Catherine Ngai
Published January 6, 2011
Antarctic Sunrise
Photograph courtesy Mel MacMahon, NSF
Dawn breaks at the IceCube Laboratory—where scientists will process the under-ice sensors' data—at the United States' Amundsen-Scott South Pole Station in September 2010.
By tracking neutrinos, the observatory may reveal new details about the physical processes behind violent cosmic events, as well as find more evidence for dark matter and dark energy, according to the IceCube website. (See "Dark Matter Proof Found Over Antarctica?")
That's because neutrinos are "astronomical messengers." Small enough to zip through the atmosphere without being damaged by most natural forces, the particles may be carrying information about the universe, the website said.
Even so, neutrinos' agility also makes them hard to detect—requiring the use of immense instruments such as the IceCube observatory.
Published January 6, 2011
Into the Ice
Photograph courtesy B. Gudbjartsson, NSF
An IceCube sensor is dropped into 1 of 86 holes drilled into the Antarctic ice in a December 2010 picture.
To reach the icy depths, scientists designed and built the Enhanced Hot Water Drill, which can penetrate more than 1.2 miles (2 kilometers) of ice in less than two days. The team then fed the IceCube detector—86 cable strings that each contain 60 neutrino sensors—into the holes.
Each cable is equipped with another four sensors at the surface, which together make up one IceCube array. The detector and arrays combine to make the IceCube Neutrino Observatory.
(Also see "First Detailed Pictures: Antarctica's 'Ghost Mountains.'")
Published January 6, 2011
Testing Equipment
Photograph courtesy B. Stock, NSF
The IceCube deployment team member tests a sensor (left, partially shown) while another scientist attaches a separate sensor to the cable (center, seen descending into the ice) in a December 2010 picture.
The observatory's main detector—separate from two auxiliary detectors—sprawls through 1.2 cubic miles (1 cubic kilometer) of ice. The South Pole, according to the IceCube website, is "the only place to find a chunk of ice big enough!"
The bigger the observatory the better, since more area increases the number of potential neutrino-water nuclei collisions that can be observed, according to an NSF statement.
(Also see "Robotic Observatory Built on Remote Antarctic Summit.")
Published January 6, 2011
Sensors in Waiting
Photograph courtesy J. Haugen, NSF
IceCube sensors—or digital optical modules—sit in the observatory's deployment tower in December 2010.
The sensors acquire and store data as well as transmit information to the IceCube Laboratory on the surface. Troubleshooting electronic problems and updating software remotely is a must—once the sensors are frozen in the ice, the team won't be able to access them again.
(Read more about Antarctica in National Geographic magazine.)
Published January 6, 2011
Drill Baby, Drill
Photograph courtesy J. Haugen, NSF
The drillhead of IceCube's Enhanced Hot Water Drill emerges from the ice in a December 2010 picture.
Drilling just one hole uses about 4,800 gallons (18,170 liters) of gasoline and melts about 200,000 gallons (757,080 liters) of ice, according to the IceCube website.
Published January 6, 2011
In the Elements
Photograph courtesy F. Descamps, NSF
Scientists participate in a cable pull to connect under-ice sensors to servers inside the IceCube Laboratory in December 2010.
To build the observatory, all the parts—and people—had to be flown in ski-equipped cargo aircraft from McMurdo Station to the South Pole, more than 800 miles (1,300 kilometers) away.
(See a high-resolution Antarctic map.)
Published January 6, 2011