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Photo, caption follows:

This 29-million-cubic-foot balloon being launched by the National Scientific Balloon Facility near McMurdo Station, Antarctica, takes a 4,000-pound research payload to 125,000 feet altitude where, if all goes well, it circumnavigates Antarctica, staying aloft 8 to 10 days to record galactic cosmic rays, gamma rays and X-rays to help understand the far reaches of the universe.
Credit: National Science Foundation

How did the Universe Begin?
Research conducted in Antarctica takes scientists to the edge of the known universe.

Extremely sensitive telescopes at the South Pole, for instance, sit at the axis of the Earth peering out into the extreme reaches of our galaxy, looking backward in time to the beginnings of the universe. Radio waves captured by the telescopes are the faint echoes of the so-called Big Bang, which allow scientists to conjecture not only how the universe began, but also its inevitable fate.

The South Pole is an ideal place to study astrophysical phenomena for a variety of reasons:

From the Earths axis, any celestial object can be observed for long periods because it remains the same elevation in the sky. South Pole astronomers have made long, continuous solar observations, some lasting more than 100 hours.

NSF’s Amundsen-Scott South Pole Station, the research home at the pole, is located atop the Antarctic ice sheet at an altitude of approximately 3,000 meters (10,000 feet). The extreme cold allows very little water vapor to form in the atmosphere. Water vapor is the principal cause of atmospheric absorption and variability in broad portions of the electromagnetic spectrum telescopes used to gather data.

Meanwhile, construction will soon begin to create a vast detector under the ice sheet that will take advantage of the extreme clarity of the ice to observe minute particles called neutrinos as they pass from space through the Earth. The detector itself will be 1 cubic kilometer, while the instruments it uses will be placed into holes drilled up to 1.5 miles into the ice.

A smaller version of the detector has already been in operation for several years. The Antarctic Muon and Neutrino Array (AMANDA) can detect and track the path of neutrinos that interact in the ice after they have passed completely through the earth. AMANDA is presently the only such high-energy neutrino telescope, with more than 500 photodetectors buried at least a half-mile below Earth's surface.

Unique Antarctic conditions near the coasts and hundreds of miles from the poles also allow scientists to harness natural phenomena for long-term astronomical observations.

Since 1988, NSF and NASA have developed techniques for flying and recovering large balloon payloads in the range of 2 tons at altitudes of roughly 37 kilometers (120,000 feet) for approximately two weeks. These techniques position the experiment above 99.7 percent of the atmosphere. For some experiments, this provides scientists with conditions as good as a ride on the space shuttle or even a satellite.

For two reasons, the unique geophysical conditions above Antarctica make long-duration balloon flights possible during the austral summer.

From October to February, Antarctica basks in nearly round-the-clock sunlight. Because direct and reflected sunlight continuously illuminate the balloon, it does not undergo the large changes in temperature, and therefore altitude, from day to night that is typical of balloon flights in temperate regions. Also, each summer for a period of a few weeks, a nearly circular pattern of gentle east-to-west winds establishes in the Antarctic stratosphere. The circulation is generated by a long-lived high-pressure area caused by the constant summertime solar heating of the stratosphere. This allows balloons to be launched and recovered relatively easily on land.

Over the past decade there have been LBD flights in most Antarctic research seasons, which run roughly from mid-December through mid-January.

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