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WHY DO ASTRONOMY AT THE SOUTH POLE?
11/22/94 J. S. Sweitzer D. A. Harper
Astronomers ask many different questions about the Universe. They get
their answers when they observe planets, stars, galaxies and glowing clouds
in space. They study these objects with different types of telescopes
from remote locations on the Earth. This is because some telescopes are
better than others at observing certain types of light. Furthermore, most
light that is not visible to our eye does not penetrate easily through
the atmosphere. For that reason, astronomers have to take their telescopes
to places where the air is the clearest. In some cases the telescopes
even have to be placed in space, like the Hubble Space Telescope. The
Hubble observes types of invisible, ultraviolet light that can't be seen
through the atmosphere at all.
Light that is at the other end of the spectrum, just beyond the color
red, is called infrared, sub millimeter and then microwave light. In this
part of the spectrum, where we cannot see the light, astronomers usually
describe the light by the length of one wave. When we are near a hot piece
of metal, we can feel infrared light even though we see nothing different.
We can't see microwave light, even though we use it to cook our food.
Beyond microwave light are the radio waves that we can detect with our
radios.
The Universe is rich with things on all scales, from planets and stars,
to galaxies and vast networks of galaxies. Current theories of the Universe
predict that the seeds for networks of galaxies should be visible as bright
and dim spots in the cosmic microwave background radiation, but these
spots are very difficult to see. Clues about the birth and the formation
of the first generation of stars come from observations of the youngest
galaxies, and modern infrared telescopes should be sensitive enough to
see these primeval galaxies. But we still have not found them in the longest
exposures. We know that stars are born continuously in dense clouds in
our Galaxy, but we still have not detected an actual star birth. We know
that planets formed around at least one star, the Sun, but we know almost
nothing about other planetary systems or how they form. Both newborn stars
and planets should be seen by sub-millimeter wave telescopes
Observations at infrared through microwave wavelengths will provide
vital clues to these mysteries. At these wavelengths, absorption and emission
by the atmosphere limit telescopes at mountain-top observatories. Yet
above the Antarctic plateau, the infrared skies are so clear and dark
that at some wavelengths, locating a telescope at the South Pole may make
it a many times better than anywhere else on Earth. At longer wavelengths
the dryness of the South Polar atmosphere will allow us to study the birth
of stars and maybe even planets. At even longer, microwave wavelengths,
the cool steady air at the Pole allows astronomers to look for the seeds
of networks of galaxies. For much less money than putting telescopes in
space, astronomers can answer exciting questions about the Universe from
the coldest place on Earth, Antarctica.
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