January 12, 2007
NORTHERN LIGHTS
RESEARCH ENTERS FINAL FRONTIER
An international
team of
scientists -- including physicists from the University
of Calgary
-- will begin gathering the
most detailed information yet about the ever-changing northern lights,
as a
multi-year research project enters its ultimate phase with the launch
of five
NASA satellites from Cape Canaveral
next
month.
Researchers in the U
of C's
Institute for Space Research will play a critical role in a
five-satellite NASA
mission called THEMIS (Time History of Events and Macroscale
Interactions
during Substorms) which is scheduled for launch at 6:07 pm (Eastern
Time) on
February 15, just over a month from today. For their part in the
program, the U
of C's THEMIS team is operating a network of Ground-Based Observatories
(GBOs)
across Northern Canada.
The THEMIS satellites
will probe dynamic processes of astrophysical interest in near-Earth
space,
while the GBOs will create mosaics of the night sky, capturing changes
in the
northern lights that are an essential part of the information needed to
answer
the questions that THEMIS is targeting. The ground and space-based
THEMIS
observations will enable scientists to pinpoint the cause of brilliant
explosions of shimmering light known as "auroral substorms."
"This is a very
exciting
moment for us because we are expecting to greatly enhance our
understanding of
these space disturbances that are both beautiful and powerful," said U
of
C physics professor Dr. Eric Donovan, leader of the Canadian component
of
THEMIS.
"The next few years
are
going to be very busy for us and our THEMIS colleagues at NASA and the University of California
at Berkeley,"
Donovan said.
The U of C operates
16 GBOs
located in communities across northern Canada (four more in Alaska are
operated
by Berkeley), which consist of automated all-sky cameras that use time
lapse
digital imaging and special optics to record auroras in the northern
skies. The
five satellites are on orbits designed so that they come together in
conjunctions over central Canada
every four days. During these conjunctions, the cameras will be used to
determine the onset of auroral substorms, while instruments on the five
satellites will provide measurements of changes in energetic particle
populations and the magnetic field in space. The mission will last at
least two
years, during which time the GBOs will record more than 200 million
photographs.
Auroras are caused by the
interaction of charged particles
from the sun, also known as the solar wind, with the Earth's magnetic
field.
Auroral substorms are the unpredictable bursts in auroral activity that
take
place when energy stored in the tail of the magnetic field is released
and
travel along magnetic lines to the polar regions where they cause
spectacular
displays of iridescent light. These storms are not fully understood and
previous studies have not been able to determine where in the
magnetosphere the
energy of the solar wind transforms into explosive auroras. Auroral
substorms
have also been linked to disturbances of telecommunications systems on
Earth
and damage to satellites.
The NASA-funded
THEMIS mission is
led by the Space Science Laboratory at the University
of California
at Berkeley,
while the Canadian component of the
project is funded by the Canadian Space Agency.
In Canada,
THEMIS will ultimately involve scientists with from the Universities of
Alberta, Saskatchewan,
New Brunswick, and Calgary, Athabasca University,
the Canadian Space Agency,
and Natural Resources Canada.
Most of the GBOs
operate in small
communities in the north including Whitehorse,
Inuvik, Sanikiluak,
and Gillam. The GBOs are run with the
generous assistance of community volunteers who help monitor and
maintain the
equipment.
"Our custodians do a
great
job of looking after the cameras and playing host to our project in
their
communities," said THEMIS Canada deployment and site manager Mike
Greffen.
"They are a critical link in a large and important NASA-CSA mission."
##
Contact:
Grady
Semmens
University
of
Calgary
403-220-7722
gsemmens@ucalgary.ca
This
text derived from:
http://www.ucalgary.ca/
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