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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