Why on earth? -- Astronomy
in Antarctica
The tools astronomers use to explore the universe work far better and
much more cost-effectively when they are located in the best place.
The most advantageous location depends on the specifics of the
experiment, and might be in space, on a high mountain, on a balloon or
aircraft, on the surface of another world, or indeed, wherever the
requirements of the experiment dictate. For example, the Hubble Space
Telescope takes advantage of its location above the disturbing effects
of the earth's atmosphere to capture superb optical images; Gemini
North exploits the special atmospheric conditions atop a 14,000 foot
Hawaiian volcano to record infrared images at the limits of
theoretical performance; and the Stratospheric Observatory for
Infrared Astronomy will carry a 100 inch telescope aloft in a 747
aircraft to capture long wavelength radiation that travels across the
reaches of space but does not penetrate down to the surface of the
earth.
The Antarctic continent provides a special opportunity and a unique
challenge. It has been known for years that the South Pole is the best
place on the planet to make sensitive wide-field infrared measurements
to search for young galaxies in the early universe and to survey
regions of star formation in our Galaxy. The extreme cold radically
improves the performance of infrared telescopes, so that a small
telescope in Antarctica outperforms a huge telescope in Hawaii for
this kind of experiment. Antarctica therefore offers the prospect of
more and better data for more astronomers at a much better price --
because small telescopes are dramatically cheaper than huge
telescopes. The kind of comprehensive astronomical survey possible
from Antarctica is important both in its own right and to set the
stage for later work: it gives us the big picture and makes sure that
future investments are properly focussed on the important
problems. The challenge of Antarctica, however, is to operate in such
a harsh environment.
A decade ago the National Science Foundation established the Center
for Astrophysical Research in Antarctica in order to begin the process
of creating an observatory at the South Pole. The early years were
spent on setting up appropriate work spaces and laboratories, on
finding out what works, and on prototyping functional astronomical
experiments. By now all the necessary components of the system have
been developed and field tested, and a demonstration is under way
using a tiny (60 cm) telescope equipped with a state-of-the-art
infrared camera on loan from the National Optical Astronomy
Observatories. Following an announcement of opportunity in late 1998,
forty-five US and twenty-two Australian experiments were proposed; the
results coming in now confirm expectations about system sensitivity
and demonstrate directly the feasibility of Antarctic infrared
astronomy.
The existence of this functional prototype, pressure from a community
of users hungry for the data, the willingness of an expert team
familiar with the issues and eager to proceed, and the in-place
infrastructure to provide support make this the right time to
establish a national facility at the South Pole. It remains only to
select and deploy the appropriate telescope, for sturdy, well-tested
telescopes of the necessary design are available as commercial
off-the-shelf items.
The team that created the prototype, a well-seasoned team of
astronomers and engineers from Boston University, Rochester Institute
of Technology, the National Optical Astronomy Observatories, the
University of Chicago, and the University of New South Wales,
Australia, and a new team member, Lowell Observatory, proposes a five
year plan to establish the Antarctic Infrared Observatory (AIRO), in
which a robotic 1.8 m telescope with a three-color infrared camera
will be prepared for Antarctic operation. After two years of
construction the system will be thoroughly field-tested (for two
years) at Lowell Observatory before shipping to the ice in the fifth
year of the program. Because access to the Antarctic site is limited
to a brief period in the summer, experience has shown that reliable
operation in Antarctica demands this kind of painstaking
preparation. It simply remains now to exploit the lessons learned in a
decade of investment by the National Science Foundation, and for the
scientific pay-off to begin through the execution of this careful and
well-developed plan.
jackson@bu.edu