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How did the universe evolve? Will the universe continue
to expand? Astronomers use a year-round observatory at
the South Pole to answer these questions, taking advantage
of the Pole's natural features: the dark, dry, and cold
environment makes for easier detection of infrared wavelengths
and small particles. Infrared and submillimeter radio
telescopes at the South Pole detect wavelengths obscured
at most other observing sites. NSF-funded researchers
use the Antarctic ice sheet to capture invisible, subatomic
particles called neutrinos in order to gain insight into
violent astrophysical events such as black hole collapses
and supernova explosions.
Another territory ripe for exploration can be found deep
below the ice. Thousands of feet under the Antarctic surface,
below the Russian-run research station known as Vostok,
lies Lake Vostok. The subglacial lake, roughly the size
of Lake Ontario, has been isolated from Earth's ecosystem
for millions of years. Cut off from the rest of the Earth,
Lake Vostok may be home to ancient species of microbes
that have been able to survive in this extreme environment.
As part of a joint U.S., French, and Russian research
project, Russian teams have drilled down into the ice
covering the lake and extracted the world's longest, deepest
ice core. They stopped drilling at about 395 feet above
the ice-water interface to prevent possible contamination
of the underlying lake by kerosene-based drilling fluid.
The upper 9,800 feet of the ice core provide a continuous
paleoclimatic record of the last 400,000 years. The record
shows that there have been four complete climatic cycles,
including four ice age or glacial periods associated with
the development of large ice sheets over the Northern
Hemisphere, and four warmer interglacial periods.
In addition, NSF-funded scientists discovered that the
core contains bacterial forms, showing that microbes existed
under the ice and probably still thrive in the lake. How
do such "extremophiles" survive? Where do they
get their energy - from geothermal activity? Studying
the microbes and their unique and isolated environment
will tell scientists more about whether life may be able
to exist in harsh conditions elsewhere in the solar system.
Indeed, Lake Vostok appears to resemble conditions on
Jupiter's frozen moon Europa. Scientists and engineers
are now working on methods to sample the subglacial lake
while preventing contamination.
Moving up in scale from microbes, biologists continue
to discover important adaptations among larger extremophiles.
In the late 1960s, physiologist Arthur L. DeVries discovered
with the help of NSF funds that Antarctic notothenioid
fish are protected from subzero temperatures by antifreeze
glycoproteins in their blood. Continuing studies to unravel
the workings of fish antifreeze could have profound implications
in a number of areas—from human organ transplantation
to agriculture and beyond. As it happens, Arctic cod have
similar glycoproteins. These proteins bind to ice crystals
and keep them from growing. Yet NSF-funded studies in
the 1990s revealed that the Arctic cod and Antarctic notothenioid
actually belong to two different orders of fish that diverged
in evolution some forty million years ago. This is a striking
case of convergent evolution in polar environments: the
fish took different routes toward the identical solution
of how to stay alive in ice water.
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National
Science Foundation -
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