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UC Berkeley U of Washington NASA NSBF, MSFC, Wallops Island, White Sands NSF |
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Introduction
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If you have any questions about the science behind the
MAXIS experiment, the aurora, or what its like to live and work
in Antarctica, please
e-mail
damien@geophys.washington.edu
and we'll try to respond as soon as we can!
You can imagine that with the cold temperatures and remote location,
working here in Antarctica would be quite a challenge. However,
there are several good reasons for launching a balloon such as ours here:
First of all, the phenomenon we are trying to observe, x-rays produced
by the aurora, occurs mainly at high latitudes, over places such
as Antarctica in the Southern hemisphere or Alaska and Scandinavia in
the Northern hemisphere. Since these x-rays do not penetrate very
far through the atmosphere the instruments to detect and image the x-rays
must be flown on a platform such as our balloon which allows us to take
measurements at high altitudes - around 120,000 feet, which is about
four times as high as most commercial airplanes fly. Also, the 24-hour daylight that
we have here in Antarctica during the summer months in the Southern hemisphere
is great for ballooning. Constant exposure to the sun allows the balloon's
electronics to be powered efficiently by solar panels. Also, since the
balloon is filled with helium gas, the constant sunlight maintains the
balloon at a stable temperature which helps maintain the altitude of the
balloon without extreme fluctuations between night and day.
We equate Antarctica with cold for obvious reasons. The
coldest temperature ever recorded on the surface of the Earth as of
1983 was measured at Vostok station (-89.6 degrees C / -129.3 degrees F)!
But during the summer months here at McMurdo Station, the temperatures
usually climb above freezing, with typical daytime temperatures near -3.6
deg. C / 30 deg. F. Oftentimes strong winds will drive this temperature much colder by
tens of degrees.
We're used to thinking of x-rays as the pictures we get of
ourselves at the doctor or dentist's office. Perhaps you've
seen "through" your carry-on baggage when it rides through the
x-ray machine at airports. So first of all,
what are x-rays? (Follow the link for an explanation) Nature produces x-rays of its own
in the upper parts of our atmosphere, especially at high latitudes
where we are doing our experiment. In this region, electrons
precipitate ("rain") down from space
(
magnetosphere). When the electrons, especially very energetic ones,
interact with the particles found in the upper atmosphere, they can give
up part or all of their energy as x-ray radiation.
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