News, Updates, and Resources for Northern Lights
Aurora Movies
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On-line Articles, News Stories
- Dec 9, 2005. Earth's
Magnetic Pole Drifting Quickly. By ALICIA CHANG,
AP Science Writer. Excerpt: SAN FRANCISCO - Earth's
north magnetic pole is drifting away from North
America and toward Siberia at such a clip that
Alaska might lose its spectacular Northern Lights
in the next 50 years, scientists said Thursday.
...The magnetic poles are part of the magnetic
field generated by liquid iron in Earth's core
and are different from the geographic poles, the
surface points marking the axis of the planet's
rotation. Scientists have long known that magnetic
poles migrate and in rare cases, swap places. Exactly
why this happens is a mystery.
"This may be part of a normal oscillation and
it will eventually migrate back toward Canada," Joseph
Stoner, a paleomagnetist at Oregon State University,
said Thursday at an American Geophysical Union meeting.
Previous studies have shown that the strength of
the Earth's magnetic shield has decreased 10 percent
over the past 150 years. During the same period,
the north magnetic pole wandered about 685 miles
out into the Arctic, according to a new analysis
by Stoner. ...At the present rate, the north magnetic
pole could swing out of northern Canada into Siberia.
...
- April 5, 2005. NASA
RELEASE: 05-089. NASA Study Finds Earth's Auroras
Are Not Mirror Image. Scientists looking at
the Earth's northern and southern auroras were
surprised to find they are not mirror images of
each other, as was once thought. The main cause
behind the differences appears to be the interaction
between the Sun's outer atmosphere and the Earth's
magnetic field. Analysis of the images from NASA's
Polar spacecraft and the Imager for Magnetopause-to-Aurora
Global Exploration (IMAGE) spacecraft showed how
the auroras move and change, based on the "tilt"
of the Earth's magnetic field toward the Sun and
conditions in the solar wind. By knowing how auroras
react to the solar wind, scientists can better determine
the impacts of space weather in the future. The new
discovery by scientists from NASA, the University
of Iowa, Iowa City, and the University of California
at Berkeley, shows that auroras may be more complicated
than previously thought. The NASA-funded study appeared
in a recent issue of Geophysical Research Letters.
See also
http://www.nasa.gov/vision/earth/lookingatearth/dueling_auroras.html
- 1 Mar 2005. The
Cosmologist and the Aurora - Essay by Dr. Sten
Odenwald (NASA scientist) about the Northern Lights
as he was observing them in Norway in winter of
2004.
- February 16, 2005. Saturn's
Auroras. Images of Saturn's polar aurora were
taken by NASA's Hubble Space Telescope on Jan.
24, 26, and 28. ...The images were obtained during
a joint campaign with NASA's Cassini spacecraft
to measure the solar wind approaching Saturn and
the Saturn kilometric radio emissions. The strong
brightening of the aurora on January 26 corresponded
with the recent arrival of a large disturbance
in the solar wind.
- Nov 8, 2004 Aurora Images:
http://www.extremeinstability.com/04-11-8.htm
- November, 2004. Aurora Gallery
http://www.spaceweather.com/aurora/gallery_01nov04_page3.htm
- Oct 2004. Aurora: Lights of Mystery. ...the aurora
borealis, through the cameras of two extraordinary
photographers, Hugh S. Rose and Patrick J. Endres,
who live beneath these awesome northern lights. Collection
of photos only available as an electronic download
file: http://www.secondnaturecd.com/2nd/aurligofmyst.html
- Jan 2, 2004. Auroras: Dancing in the Night, by
Don Pettit. NASA Earth Observatory. If Iris, the
goddess of the rainbow, had a sister she would be
the goddess of Aurora. Glowing green ripples form
arcs that constantly transform their shape into new
glowing diaphanous forms: there is nothing static
about aurora. It is always moving, always changing,
and like snowflakes, each display is different from
the last. http://earthobservatory.nasa.gov/Study/ISSAurora/
- July 8, 2002 Auroras
Underfoot -- A group of astronauts
will never forget the day they flew right through
a cloud of auroras.
- October 25, 2001 EARTH'S
AURORAS MAKE RARE JOINT APPEARANCE IN A FEATURE
FILM Scientists using NASA's Polar spacecraft
have captured the first-ever movie of auroras dancing
simultaneously around both of Earth's polar regions.
During a space weather storm on October 22, Polar's
Visible Imaging System observed the aurora borealis
and aurora australis (northern and southern lights)
expanding and brightening in parallel at opposite
ends of the world. The images confirm the three-century
old theory that auroras in the northern and southern
hemispheres are nearly mirror images - conjugates
- of each other.
- Nov. 19, 2001 IT'S
ABOUT TIMED: NASA SPACECRAFT WILL
USE LOFTY PERCH TO STUDY GATEWAY TO SPACE
A NASA mission will soon reveal the well-kept secrets
of a mysterious region situated 40 to 110 miles (about
60 to 180 kilometers) above the Earth called the
Mesosphere and Lower Thermosphere/Ionosphere (MLTI),
where electrical currents surge and auroras cast
an eerie glow over the Northern and Southern hemispheres.
RELEASE: 01-226 Mission site:
http://stp.gsfc.nasa.gov/missions/timed/timed.htm
- Nov. 6, 2001 THE
SUN'S DARK SECRET: HOW SUNSPOTS PULL THEMSELVES
TOGETHER Scientists now have the first clear
picture of what lies beneath sunspots, enigmatic
planet-sized dark areas on the Sun's surface,
and have peered inside the Sun to see swirling
flows of electrified gas or plasma that create
a self-reinforcing cycle, which holds a sunspot
together.RELEASE: 01-216
- 25 July 2001 NASA's
Wind spacecraft flies through Earth's magnetic
tail and captures rare event in action
- May 1, 2001, Space
Weather on Mars [Science@NASA]
- SUN UNLEASHES RECORD SUPERFLARE, EARTH DODGES
SOLAR BULLET -- NASA
RELEASE: 01-66
- Apri 1, 2001 A massive coronal mass ejection
afew days earlier resulted in unusual displays
of aurora at lower latitudes. Wayne Narron, Northern
Lights field tester, captured a photo from 30° north
latitude.
- March 27, 2001 COLLIDING SOLAR ERUPTIONS PACK
POWERFUL MAGNETIC PUNCH -- RELEASE:
01-56
- March 8, 2001 POSTCARDS
FROM JUPITER: NEW AURORA DETAILS SEEN
- December 15, 2000 Hubble
sees satellite footprints in Jupiter aurora
- 18 December 2000 Uncovering
the mysteries of Jupiter's aurora
- Dec 14, 2000 Satellite
Footprints Seen in Jupiter Aurora
- Nov 2000, Sky & Telescope magazine,
review
of Aurora Monitor software that predicts
potential aurora activity. p. 72. http://solar.spacew.com/aurora/
- Jupiter
Auroral Campaign Dec. 2000
- February 4, 1999 SOHO SPACECRAFT DETECTS SOURCE
OF HIGH-SPEED SOLAR "WIND" -- RELEASE:
99-11
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More activities
- Want More Sun? Planetarium Activity "Going
Further" on the concept of Midnight Sun: Time the
duration of daylight with wristwatches or stop watches
at a sequence of locations from the equator north
(or south). It is sufficient to time the Sun's travel
from the meridian to sunset and double the result.
The idea of this activity is in the Proceedings of
the 35th Annual Conference of the Middle Atlantic
planetarium Society (MAPS) May, 2000,by Sam Storch,
Director of the Hubble Planetarium in Brooklyn, NY,
and based on an idea by George Reed. Here are some
locations to use:
0° Equator; 10°N Port of Spain, Trinidad;
20°N Mexico City; 26°N Miami, FL; 28°N
Cape Canaveral; 30°N New Orleans, LA; 34°N
Los Angeles, CA; 38°N San Francisco, CA; 40°N
NewYork; 42°N Boston; 45°N Montreal; 47°N
Quebec; 60°N Leningrad, Russia; 65°N Fairbanks,
AK; 70°N Point Barrow, AK.
- For Colors of the Aurora activity, p. 45--online
spectra: http://www.colorado.edu/physics/2000/quantumzone/
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Hard Copy Articles
- Burtnyk, Kimberly, Anatome of an Aurora , Sky
& Telescope magazine, March 2000. L Eather, Robert
H., An Aurora Watcher's Guide, Sky &
Telescope magazine,
March 2000.
- Frank, Adam, Blowin' in the Solar Wind,
Astronomy magazine,
Oct 1998, p. 60. Scientists are using the latest
satellites and supercomputers to predict the onslaught
of space storms.
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- Jago, Lucy, The Northern Lights,
Alfred A. Knopf, New York, 2001. True story of Kristian
Birkeland and his theories about the aurora borealis.
From Astronomy magazine, March
2000, p. 97:
Question: Earth's magnetic field has flip-flopped in the past.
If this were to happen today, would it happen gradually or suddenly,
and what would be the effect on life?
Charles Harrison, Rogersville, MO.
Answer from Eugene H. Levy, University of Arizona: Earth's
magnetic field has changed polarity many times throughout our
planet's history. The record of these geomagnetic reversals
is preserved in layers of sediment, in rocks formed from lava,
and in the magnetization of the seafloor crust.
Geomagnetic reversals occur at random intervals, ranging
from a few tens of thousands of years to more than a million
years. On the average, the field revereses about once every
200,000 years. From a geological perspective, a reversal event
occurs very quickly, taking about 5,000 years. During a reversal,
the magnetic field does not completely disappear. Instead,
the field dimishes to about 20% of its usual strength and temporarily
takes on a relatively disordered strurcture.
Earth's magnetic field provides some shielding from cosmic
rays, so during a reversal the cosmic radiation striking Earth
increases. Because the atmosphere provides our main shield
against cosmic rays, the increase in cosmic radiation is not
a cause for alarm. Thjere is likely to be some effect on climate
during a field reveresal. But we do not yet understand the
mechanisms well enough to predict the nature or magnitude of
the effects.
Although there ar likely to be some minor effects on life,
including possible small increases in mutation rates induced
by the moderate increase in cosmic rays, there is not evidence
that magnetic reversals have a significant negative effect
on life. Organismsthat rely on magnetic orientation during
migration might be disrutpted. But reversla events are so slow
thaqt some adaptation is likely to occer.
The last major reversal occurred about 700,000 years ago,
when human ancestors already were relatively advanced. During
the 3 million years that have elapsed since the time that putative
humanoid ancestors dwelled in Africa, Earth's magnetic field
has reversed about a doaen times with no significant disturbance
to life.
Earth's magnetic field changes slowly during a reversal event.
Even in normal times, the intensity of Earth's magnetic field
commonly varies by as much as 50 % over a few thousand years.
In fact, while the magnetic field intensity has decreased a
few percent over the past 100 years, there is no reason to
believe that (and no way to tell if) Earth's magnetic field
is entering a reversal phase. This decrease is probably just
a reflection of normal "geomagnetic weather" and the intensity
will likely increase in the future. But the pasts is a reliabloe
guide to the future. It is virtually certain that Earth's magneticf
field will reverse many times more in the future, with no cause
for alarm.
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From Sky & Telescope magazine,
March 2000 p. 24:
Ganymede Glows
Even if Galileo spacecraft hadn't discovered a magnetic field
enveloping Ganymede, space physicists would still know that somthing
odd was going on there. in recent years they have deduced that
Jupiter's largest moon has a tenuous atmosphere of oxygen and
ozone (O3) and a larger corona of atomic hydrogen. Spectroscopic
observation by the Hubble Space Telescope in mid-1996 even revealed
faint fluorescence from oxygen atoms at ultraviolet wavelengths.
Their interest piqued by these prior discoveries, two research
teams were recently surprised to find that the moon has a double
glow: an ultraviolet emission at the poles and a distinctly red
one around the equator.
A team led by Paul D. Feldman (Johns Hopkins University)
and Melissa A. McGrath (Space Telescope Science Institute)
used HST to image the faint ultraviolet auroras enveloping
Ganymede's polar regions. the auroras result when electrons
in Jupiter's magnetosphere flow along magnetic field lines
leading tgoward the poles. There they break up oxygen molecules
in Ganymede's tenuous atmosphere; the resulting excited oxygen
atoms emit ultraviolet light at wavelengths of 1304 and 1356
angstroms.
Meanwhile, the wisps of gas surrounding Ganymede's midsection
are fluorescing in red light bright enough to be seen by some
future astronaut standing on the surface. Last Augusts, on
two nights when Ganymede was in Jupiter's shadow, Michael E.
Brown and Antonin Bouchez (Cal Tech) used the Keck I telescope
to record the red light emitted by oxygen atoms at 6300 angstroms.
Not an aurora in the usual sense, this emission is instead
concentrated over the equator, a region protected by the moon's
magnetic field from direct bombardment from the Jovian
magnetosphere...
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