This is a copy of the notes that Walt Farmer gave me to accompany the pictures I showed at the Jackson Amateur Radio Operators convention. I clearly omitted some of the text (I hate just reading notes to an audience), misread other stuff, and ad libbed outrageously. That I could give the presentation at all is due to all the hard work that Walt put into finding and organizing these pictures.
The actual pictures are available by clicking on the links and also contained in the directory “combined”. You should be able to download them by clicking here
Many thanks to Walt (happy 60th birthday) for putting this all together
Also thanks to the audience members for their attention, and the warm welcome they gave both me and Liberty (my daughter) who ran the slideshow from the computer.
Victor A. Wagner Jr.
vawjr@rudbek.com
APOD:
August 18, 1999 - Sun Block
Explanation:
During a total solar eclipse, Earth's
moon blocks the sun - almost exactly. While the sun
is about 400 times wider than the moon, it is also about 400 times
farther away and each appears to be half a degree or so in diameter.
On
August 11, this remarkable coincidence in the
apparent size of two vastly different celestial bodies produced
tantalizing solar spectacles for denizens of Europe and Asia. For
example, prominences along the sun's limb peer around the moon's dark
edge in this
dramatic picture of totality recorded as the lunar
shadow swept across Hungary. Subtle structures in the sun's inner
corona are also visible streaming beyond the silhouetted moon. This
total eclipse of the sun was the last to grace
planet Earth's skies for the last millennium.
APOD:
2003 November 22 - Moon AND Sun
Explanation:
This composite image was made from 22 separate pictures of the
Moon and Sun all taken from Chisamba,
Zambia during the total phase of the 2001
June 21 solar eclipse. The multiple
exposures were digitally processed and combined to
simultaneously show a wealth of detail which no single camera
exposure or naked-eye observation could easily reveal. Most striking
are the incredible flowing streamers of the Sun's outer atmosphere or
solar
corona, notoriously difficult to see except when
the
new Moon blocks the bright solar disk. Features on
the darkened near side of
the Moon can also be made out, illuminated
by sunlight reflected from a
full Earth. A giant solar prominence seems
to hang just beyond the Moon's eastern (left) edge
while about one diameter farther east of the eclipsed Sun is the
relatively
faint (4th magnitude) star 1
Geminorum.
APOD:
2005 October 5 - An Annular Solar Eclipse at High Resolution
Explanation: On Monday, part of the Sun
went missing. The missing piece was no cause for concern -- the Moon
was only momentarily in the way. The event was not a total
eclipse of the Sun for any Earth-bound sky
enthusiast but rather, at best, an annular
eclipse, where the Moon
blocked most of the Sun. Because of the relatively
large distance to the Moon during this Earth-Moon-Sun alignment, the
Moon did not have a large enough angular
size to block the entire
Sun. Those who witnessed the solar eclipse from a
narrow
path through Portugal,
Spain
and Africa,
however, were lucky enough to see the coveted Ring
of Fire, a dark Moon completely surrounded by the
brilliant light of the distant Sun. Pictured
above is a Ring
of Fire captured in unusually high resolution above
Spain. The resulting image shows details of the granular
solar surface as well as many prominences
around the Sun.
APOD:
2006 April 7 - The Crown of the Sun
Explanation:
During
a total solar eclipse, the
Sun's extensive outer atmosphere or corona is an
awesome
and inspirational sight. The subtle shades and shimmering features of
the corona that
engage the eye span a brightness range of over
10,000 to 1, making them notoriously difficult to capture in a single
picture. But this composite of 33 digital images ranging in exposure
time from 1/8000 to 1/5 second comes very close to revealing the
crown of the Sun in all its glory. The
telescopic views were recorded from Side, Turkey
during the March 29 solar eclipse, a
geocentric celestial event
that was widely
seen under nearly
ideal conditions. The composite also captures a
pinkish prominence extending just beyond the upper edge of the
eclipsed
sun.
APOD:
June 16, 1998 - An Active Region of the Sun
Explanation:
The Sun
is a busy place. This
false-color image depicts an active region near an
edge of the Sun.
Hot plasma
is seen exploding off the Sun's
photosphere and traveling along loops defined by
the Sun's
magnetic field. The red regions are particularly
hot, indicating that some magnetic field loops carry hotter gas than
others. These active loops were so large that the Earth
could easily fit under one. The TRACE
satellite was launched in April 1998 with plans to continue
high-resolution imaging as the Sun passes Solar
Maximum in 2001.
APOD:
2004 December 6 - Filaments Across the Sun
Explanation:
Two unusually long filaments crossed part of the Sun last week.
The filaments
are actually relatively cool and dark prominences
of solar plasma
held up by the Sun's magnetic
field but seen against the face
of the Sun. Filaments typically last a few weeks
before falling back. Pictured
above, the two filaments are visible on the Sun's
right side. It would take twenty Earths, set end-to-end, to match the
length of one of the filaments.
Also visible are bright hot regions called plages
and a carpet of hundreds of granules
that provide the Sun's texture. The above
image was taken through a small telescope in a very
specific
color of light emitted primarily by hydrogen.
APOD:
2004 July 25 - A Solar Filament Lifts Off
Explanation:
Hot gas frequently erupts from the Sun. One such eruption
produced the glowing filament pictured
above, which was captured in 2000 July by the
Earth-orbiting TRACE
satellite. The filament, although small compared to
the overall size of the Sun,
measures over 100,000 kilometers in height, so that the entire Earth
could easily fit into its outstretched arms. Gas in the filament is
funneled by the complex and changing magnetic
field of the Sun. After lifting
off from the Sun's
surface, most of the filamentary
gas will eventually fall back. More powerful solar
eruptions emit particles that reach the Earth and
can
disrupt manmade satellites. The cause and nature of
solar
eruptions are the topic of much research.
APOD:
2004 August 2 - Spicules: Jets on the Sun
Explanation:
Imagine a pipe as wide as a state and as long as half the Earth.
Now imagine that this pipe is filled with hot
gas moving 50,000 kilometers per hour. Further
imagine that this pipe is not made of metal but a transparent
magnetic
field. You are envisioning just one of thousands of
young spicules on the active
Sun. Pictured above is perhaps the highest
resolution image yet of these enigmatic solar flux tubes. Spicules
dot the above
frame of solar active region 10380 that crossed the
Sun in June, but are particularly evident as a carpet
of dark tubes on the right. Time-sequenced images have recently shown
that spicules
last about five minutes, starting out as tall tubes of rapidly rising
gas but eventually fading as the gas peaks and falls back down to the
Sun. These images also indicate, for the first time, that the
ultimate cause of spicules
is sound-like waves that flow over the Sun's
surface but leak into the Sun's
atmosphere.
APOD:
April 30, 1999 - Solar Shock Wave
Explanation:
On September 24, 1997 a shock
wave blasted across the surface of the sun at
speeds of 250 to 600 kilometers per second. On planet Earth,
observer Barry Reynolds photographed the expanding shock front (left)
in the light
emitted by hydrogen atoms at the solar surface. His
discovery image was nicely confirmed by a space-based extreme
ultraviolet image (right) of the shock ramming through the sun's
upper atmosphere as recorded by the SOHO satellite
observatory. In both pictures a bright solar
flare is seen near the center of a circular
arc-like feature representing a shock front. The shock front is dark
in the ground based photo and bright in the ultraviolet image. These
shock fronts are believed to be tracers of a 3-dimensional
disturbance caused by the flare but researchers are uncertain as to
the exact physical mechanisms which produced it. Along with other
violent events called coronal mass ejections, solar flares are known
to generate
streams of energetic particles which can affect the
Earth's magnetosphere and Earth orbiting satellites.
Gawxcompar.gif is 2 images of the sun, taken at the same time, in the xray spectrum & in white light. Spots can easily be seen in white light.
APOD:
2003 October 29 - A Powerful Solar Flare
Explanation:
Yesterday,
our Sun produced one of the most
powerful solar flares in recorded history. Seen
across the electromagnetic
spectrum, the Sun
briefly became over 100 times brighter in X-rays
than normal. Over the next few days, as energetic
particles emitted from these regions strike the
Earth, satellite communications might be affected and auroras might
develop. The flare
and resulting CME,
emitted from giant
sunspot group 10486, was captured
above as it happened by the by the LASCO
instrument aboard the Sun-orbiting SOHO
satellite. The disk of the Sun is covered
to accentuate surrounding areas. The time-lapse movie shows the
tremendous
explosion in frames separated in real time by about
30 minutes each. The frames appear progressively noisier as protons
from the flare
begin to strike the detector. The SOHO satellite has been put in a
temporary safe mode to avoid damage from the solar particle storm.
APOD:
2002 May 16 - Double Trouble Solar Bubbles
Explanation:
During April and May, attention has been focused on the western
evening sky, presenting its spectacle of bright
planets and crescent moons
shortly after sunset. Meanwhile,
the Sun
itself has not been just sinking quietly below the horizon. For
example on
May 2nd, two enormous clouds of energetic particles
blasted away from the solar surface in nearly simultaneous eruptions.
Known as coronal
mass ejections (CMEs), they appear as large
"bubbles" oriented at about 2 o'clock and 8 o'clock in this
composite image from cameras onboard the sun-staring SOHO spacecraft.
At picture center, an extreme ultraviolet image of the Sun recorded
near the time of these eruptions has been superimposed for scale. The
blank region surrounding it corresponds to an occulting disk in one
of SOHO's coronagraphic
cameras. Speeding outward
at millions of kilometers per hour, these two CMEs
missed our fair
planet. But those that do impact
Earth's magnetosphere often trigger auroral
displays and disruptions.
APOD:
2003 October 27 - Large Sunspot Groups 10484 and 10486
Explanation:
Two unusually large sunspot
groups are now crossing the face of the Sun.
Each group, roughly the size of Jupiter,
is unusual not only for its size but because it is appearing over
three years after solar
maximum, the peak of solar surface activity.
Sunspot
group 10484 appears near the image center, while sunspot
group 10486 is just coming over the left limb of the Sun. The active
region associated with Sunspot 484 (the shorter nickname) has already
jettisoned a large coronal
mass ejection (CME) of particles
out into the Solar
System. When striking Earth, radiation of this sort
has the power to interrupt normal satellite
operations while simultaneously providing beautiful
auroras. Rotating with the Sun, sunspots
484 and 486 will take about 30 days to make one
complete
circle, slowly evolving in size and shape during
this time. After using extreme care never
to look directly at the Sun, the above image was
created by holding a digital camera up to a small telescope.
APOD:
2001 April 11 - Large Sunspot Group AR 9393
Explanation:
The largest sunspot
group of the past ten years crossed the surface of the Sun
late last month and early this month. The group was designated Active
Region 9393 as it was the 9393rd region identified
since counting
officially began in 1973. The number of active
regions on the Sun is high recently because the Sun
is reaching the maximum of its current 11-year
cycle of magnetic activity. The above
time-lapse sequence shows AR 9393 as it evolved
from 27 March to April 2 to become over 10
times larger than our
Earth. Just after the end of the movie, on April 2,
AR
9393 unleashed the largest
solar flare of the last
25 years. Luckily, the flare
was not pointed toward the Earth, or flare
particles might have damaged satellites or even
caused
local electrical blackouts. Yesterday morning,
however, a less powerful flare was ejected from a different sunspot
group (AR 9415) toward Earth that has already caused radio
interference.
APOD:
2004 July 26 - A Large Active Region Crosses the Sun
Explanation:
An unexpectedly large sunspot region is now crossing the Sun. The
active
region is home to rivers of hot plasma,
explosive flares,
strong magnetic
fields, a powerful Coronal
Mass Ejection (CME), and a sunspot
group so large it can be seen by the protected eye
without magnification. In fact, this
region appears larger than Venus
did when it crossed the Sun last month.Pictured
above is a close-up of this sunspot
group. Energetic ions
from sunspot group 652 continue to impact the Earth and create rare
purple
auroras.
APOD:
2005 February 16 - Sunspot Metamorphosis: From Bottom to Top
Explanation: Sunspots -- magnets the
size of the Earth -- are normally seen flat on the Sun. The above
digital metamorphosis, however, shows a sunspot
as it appears at increasing heights, effectively in three dimensions.
The above
false-colored image sequence of solar active region
AR 10675 was taken in three very specific colors that effectively
isolate different
layers above the solar surface. The first images
show the Sun's photospheric surface as it normally appears, covered
with granules.
The large dark sunspot
sports a clear dark umbra
in the center surrounded by a lighter penumbra. Images appearing
toward the middle of the sequence show the Sun
as in light predominantly emitted a few hundred kilometers above the
photosphere.
At this height, the continent sized bubbling
granules appear reversed, and long lines of
constant magnetic
force begin to appear. The last images show the Sun at a few thousand
kilometers into the chromosphere.
Here magnetic
field lines can be clearly followed outward from
the sunspot
to distant regions.
APOD:
2005 November 6 -A Sunspot Up Close
Explanation:
Why would a small part of the Sun appear slightly dark? Visible
above is a close-up picture of a sunspot,
a depression on the Sun's face that is slightly cooler and less
luminous than the rest of the Sun.
The Sun's complex magnetic
field creates this cool region by inhibiting hot
material from entering the spot.
Sunspots
can be larger
than the Earth and typically last for only a few
days. This
high-resolution picture also shows clearly that the
Sun's face is a bubbling sea of separate cells of hot
gas. These cells are known as granules.
A solar
granule is about 1000 kilometers across and lasts
about 10 minutes. After that, many granules
end up exploding.
APOD:
2002 November 14 - The Sharpest View of the Sun
Explanation:
This stunning image shows remarkable and mysterious details near
the dark central region of a planet-sized sunspot
in one of the
sharpest views ever of the surface of
the Sun. Just
released, the picture was made using the Swedish
Solar Telescope now in its first year of operation
on the Canary Island of
La Palma. Along with features described as hairs
and canals are dark cores visible within the bright filaments that
extend into the sunspot, representing previously unknown and
unexplored solar
phenomena. The filaments' newly revealed dark cores
are seen to be thousands of kilometers long but only about 100
kilometers wide. Resolving features 100 kilometers wide or less is a
milestone in solar
astronomy and has been achieved here using sophisticated adaptive
optics, digital image stacking, and processing techniques to counter
the blurring
effect of Earth's atmosphere. At optical wavelengths,
these images are sharper than even current space-based
solar observatories can produce. Recorded on 15
July 2002, the sunspot shown is the largest of the group of sunspots
cataloged as solar active region AR
10030.
Iqspotgraph is a display of the sunspot cycle: 5.5 yrs. to 11 yrs. to 22 yrs. for magnetic polar reversal.
APOD:
2003 February 23 - A Twisted Solar Eruptive Prominence
Explanation:
A huge eruptive prominence is seen moving out from our Sun
in this condensed half-hour time-lapse sequence. Ten Earths
could easily fit in the "claw" of this seemingly solar
monster. This large prominence, though, is significant not only for
its size, but its shape. The twisted figure eight shape indicates
that a complex magnetic
field threads through the emerging solar
particles. Recent
evidence of differential rotation inside the Sun
might help account for the surface explosion. The
sequence was taken early in the year 2000 by the
Sun-orbiting SOHO
satellite. Although large
prominences and energetic Coronal
Mass Ejections (CMEs) are relatively rare, they are
occurred more frequently near Solar
Maximum, the time of peak sunspot and solar
activity in the eleven-year solar
cycle.
APOD:
2004 March 30 - A Prominent Solar Prominence from SOHO
Explanation:
One of the most spectacular solar sights is a prominence. A solar
prominence is a cloud of solar gas held above the
Sun's surface by the Sun's magnetic
field. Last month, NASA's Sun-orbiting SOHO
spacecraft imaged an impressively
large prominence hovering over the surface,
pictured
above. The Earth
would easily fit under the hovering curtain
of hot gas. A quiescent prominence
typically lasts about a month, and may erupt in a
Coronal
Mass Ejection (CME) expelling
hot gas into the Solar
System. Although somehow related to the Sun's
changing magnetic
field, the energy mechanism that creates and
sustains a Solar
prominence is still a topic of research.
APOD:
2005 November 9 - A Solar Prominence from SOHO
Explanation:
What happened to the Sun? Nothing very unusual: the
strange-looking solar
appendage on the lower left is actually just a
spectacular looking version of a common solar
prominence. A solar
prominence is a cloud of solar gas held above the
Sun's surface by the Sun's magnetic
field. Pictured
above in 2002 October, NASA's Sun-orbiting SOHO
spacecraft imaged an impressively
large prominence hovering over the surface,
informally dubbed a flame. Over 40 Earths
could line up along the vast length of the fireless
flame of hovering hot gas. A quiescent prominence
typically lasts about a month, and may erupt in a
Coronal
Mass Ejection (CME) expelling
hot gas into the Solar
System. Although somehow related to the Sun's
changing magnetic
field, the energy mechanism that creates and
sustains a Solar
prominence is still a topic of research.
APOD:
2003 July 7 - At the Edge of the Sun
Explanation:
Dramatic prominences
can sometimes be seen looming just beyond the edge of the sun. A
solar
prominence is a cloud of solar gas held just above
the surface by the Sun's
magnetic field. The Earth
would easily fit below the prominence
on the left. A quiescent
prominence typically lasts about a month, and may
erupt in a Coronal
Mass Ejection (CME) expelling hot gas into the
Solar
System. Although very hot, prominences typically
appear
dark when viewed against the Sun,
since they are slightly cooler than the surface. The above
image in false color was taken from Stuttgart,
Germany
with an amateur telescope and camera.
APOD:
2000 September 28 - Heating Coronal Loops
Explanation:
Extending above the photosphere or visible surface of the
Sun, the faint, tenuous solar
corona can't be easily seen from Earth, but it is
measured to be hundreds of times hotter than the photosphere itself.
What
makes the solar corona so hot? Astronomers have
long sought
the source of the corona's heat in magnetic
fields which loft monstrous loops of solar
plasma
above the photosphere. Still, new
and dramatically
detailed observations of
coronal loops from the orbiting TRACE
satellite are now pointing more closely to the
unidentified energy source. Recorded in extreme ultraviolet light,
this
and other TRACE images indicate that most of the
heating occurs low in the corona, near the bases of the loops as they
emerge from and return to the solar surface. The new
results confound the conventional theory which
relies on heating the loops uniformly. This tantalizing TRACE image
shows clusters
of the majestic, hot coronal loops which span 30 or more times the
diameter of planet Earth.
APOD:
2000 June 8 - Active Regions, CMEs, and X Class Flares
Explanation:
Space
Weather forcasters are predicting major storm
conditions over the next few days as the active
Sun has
produced at least three strong flares and a large
coronal mass ejection (CME) since Tuesday,
June 6th. This recent
false color X-ray
image of the Sun shows the active region generating
the explosive events, here the
Sun's most intense source of
X-rays, as the dominant bright area just above
center. X-ray hot plasma suspended in looping magnetic fields arcs
above this region, cataloged as AR9026. AR9026 appears as a large
group of sunspots
in visible light images. The three intense flares were all X-class
events, the most severe class of solar flares based on X-ray flux
measurements
by the earth-orbiting GOES
satellites. Energetic particles from the
CME, associated with the second X-class flare, were
directed
toward planet Earth and could produce geomagnetic
storms as early as today. Possible effects range
from increased auroral
displays to disruptions of satellite and
communications systems and electrical power grids.
APOD:
2000 March 9 - Sun Storm: A Coronal Mass Ejection
Explanation:
Late
last month another erupting filament lifted
off the active solar surface and blasted this
enormous bubble of magnetic
plasma into space. Direct light from the sun is
blocked in this picture of the event with the sun's relative position
and size indicated by a white half circle at bottom center. The field
of view extends 2 million kilometers or more from the solar surface.
While hints of these
explosive events, called coronal
mass ejections or CMEs, were discovered by
spacecraft in the early 70s this dramatic image is part of a detailed
record of this CME's development from the presently operating SOlar
and Heliospheric Observatory (SOHO) spacecraft. Near the minimum of
the solar
activity cycle CMEs occur about once a week, but as
we approach solar maximum rates of two or more per day are
anticipated. Though this CME was clearly not headed
for Earth, strong CMEs are seen to profoundly influence space
weather, and those directed toward our planet and
can have serious
effects.
Next two images use the same description..
APOD:
January 23, 1998 - Jovian Aurora
Explanation:
These two recently released
Hubble Space Telescope close-ups show the Northern
and Southern lights ... on
Jupiter. Like
aurora on Earth, these Jovian aurora
are caused by charged particles funneled into the
atmosphere above the planet's North (right) and South poles by
magnetic
fields. But Jupiter's magnetic field is extremely
large and ionized material expelled from the
volcanic moon Io is trapped in it creating light
shows 1,000 times more intense than Earth's
auroral storms. Charged particles released by Io
are also funneled along magnetic flux tubes which form a direct
"bridge" to the Jovian atmosphere. The result is auroral
hot spots - magnetic footprints 600 or more miles across which race
over Jupiter's
cloud tops. A hot spot is visible in both images as
a comet-like feature just outside the polar
auroral rings. In these false color ultraviolet
images, Jupiter's limb (edge) appears dull brown while the
auroral displays are shades of white and blue.
APOD:
January 9, 1998 - Saturnian Aurora
Explanation:
Girdling the
second largest planet in the Solar System, Saturn's
Rings are one of the most spectacular sights for
earthbound telescopes. This
recently released image, from the orbiting Hubble
Space Telescope's STIS instrument, offers a
striking view of another kind of ring
around Saturn - pole
encircling rings of ultraviolet
aurora. Towering more than 1,000 miles above the
cloud tops, these Saturnian auroral displays are
analogous
to Earth's. Energetic charged particles in the
Solar Wind are funneled by the planet's magnetic
field into polar regions where
they interact with atmospheric gases. Following the
ebb and flow of Saturn's aurora, researchers can remotely explore the
planet's atmosphere and magnetic field. In this false color image,
the dramatic red aurora identify emission from atomic hydrogen, while
the more concentrated white areas are due to hydrogen molecules. In
2004, NASA began making close-up studies of the Saturnian system with
the
Cassini Spacecraft
APOD:
December 30, 1996 - X-Ray Earth
Explanation:
The Earth glows in many kinds of light, including the energetic X-ray
band. Actually, the Earth
itself does not glow - only aurora
produced high in the Earth's
atmosphere. Above is the first
picture of the Earth in X-rays, taken in March with
the orbiting Polar
satellite. Bright X-ray
emission is shown in red. Energetic
ions from the Sun cause aurora
and energize electrons
in the Earth's
magnetosphere. These electrons move along the
Earth's
magnetic field and eventually strike the Earth's
ionosphere, causing the X-ray emission. These
X-rays are not dangerous because they are absorbed by lower parts of
the Earth's atmosphere.
APOD:
2004 July 30 - Northern Lights
Explanation:
While enjoying the spaceweather
on a gorgeous summer evening in mid-July, astronomer Philippe
Moussette captured this colorful
fish-eye lens view looking north from the
Observatoire
Mont Cosmos, Quebec, Canada, planet Earth. In the
foreground, lights along the northern horizon give an orange cast to
the low clouds. But far above the clouds, at altitudes of 100
kilometers or more, are alluring green and purple hues of the aurora
borealis or northern
lights, a glow powered by energetic particles at
the edge of space. In the background are familiar stars of the
northern sky. In particular, that famous celestial kitchen utensil,
the Big
Dipper (left), and the W-shaped constellation
Cassiopeia (right) are
easy to spot. Then, just follow
the pointer stars of the Big Dipper to
Polaris, perhaps the most famous
northern light of all.
APOD:
2002 October 31 - Aurora in the Night
Explanation:
Traveling shock waves from
the Sun and solar wind gusts have buffeted planet
Earth's magnetosphere. As a result, skywatchers at
high latitudes in the northern hemisphere were treated
to many displays
of the aurora borealis or northern lights. For
example, on the first of October this particularly
ghostly apparition
was photographed looming above the horizon near the
town of
Inari in northern Finnish Lapland.
APOD:
2004 November 9 - A Full Sky Multicolored Auroral Corona
Explanation: On some nights the sky is
the most interesting show in town. This fisheye
picture captures a particularly active and colorful auroral
corona that occurred two days ago over
l'Observatoire de la Decouverte in Val Belair near Quebec,
Canada.
The above spectacular aurora has an unusually high degree of detail,
range of colors,
and breadth across the sky. The vivid green, red, and blue auroral
colors are likely caused by high atmospheric oxygen
and hydrogen
reacting to incoming electrons.
The trigger events were magnetically
induced explosions on the Sun.
APOD:
2005 August 7 - Dueling Auroras
Explanation:
Will it be curtains for one of these auroras? A quick inspection
indicates that it is curtains for both, as the designation "curtains"
well categorizes the type of aurora pattern pictured. Another
(informal) type is the corona.
The above
auroras resulted from outbursts of ionic
particles from the Sun
during the last week of 2001 September. A polarity
change in the solar
magnetic field at the Earth
then triggered
auroras. The above
picture was taken on 2001 October 3 as fleeting
space radiation pelted the Earth's
atmosphere high above the Yukon
in Canada.
APOD:
2000 August 17 - Mount Megantic Magnetic Storm
Explanation:
Plasma from the Sun and debris from a comet both collided with
planet Earth last Saturday morning triggering magnetic
storms and a meteor shower in a dazzling
atmospheric spectacle. The debris stream from comet
Swift-Tuttle is anticipated
yearly, and many
skygazers already planned to watch the peak of the
annual
Perseids meteor shower in the dark hours of August
11/12. But the simultaneous, widely
reported auroras
were triggered by the chance arrival of something
much less predictable -- a solar coronal
mass ejection. This massive bubble of energetic
plasma was seen leaving the active Sun's surface just in time to
travel to Earth and disrupt the planet's magnetic
field triggering extensive
auroras during the meteor shower's peak! Inspired
by the cosmic light show, Sebastien Gauthier photographed
the colorful auroral displays.
APOD:
2003 November 13 - Aurora Oklahoma
Explanation:
Nestled in the central US, the state of Oklahoma is noted for its
gorgeous
prairie skies and wide-open spaces, but not for
frequent visitations of the
northern lights. Still, following the intense solar
activity late last month, aurora did come sweeping
down the Oklahoma plains and skywatcher
Dave Ewoldt managed to catch up with this photogenic apparition 40
miles northwest of Oklahoma City at about 3am CST. Anticipating
aurora
sightings, Ewoldt had spent the evening
photographing nighttime
views of small towns in the area while keeping an eye toward the
north. He
reports, "I was just about ready to call it a
night when the show started. When it did, it was like someone turned
on a lightswitch. I wish it would have lasted longer... [it] seemed
like it was completely done in about 25 minutes." Watery
reflections of the colorful show highlight the foreground in the
stunning image while stars of the Big Dipper and the northern sky
shine behind the dazzling Oklahoma
auroral display.
APOD:
2002 October 15 - Aurora's Ring
Explanation:
Gusting solar
winds and blasts
of charged particles from the Sun made the early days of October
rewarding ones for those anticipating
auroras. While out enjoying the stormy space
weather from Toemmeraas, Norway, Trygve Lindersen
recorded this picturesque
apparition of the northern lights with a digital
camera on October 6. From this perspective, the curtains of green
light formed a ring which seemed to hover,
wraithlike, just above the foreground trees. But
the ring of light was actually 100 kilometers or more above
the trees and the greenish glow produced by oxygen
molecules interacting with energetic electrons and fluorescing near
the edge of space.
APOD:
2005 November 5 - Aurora from Space
Explanation:
From the ground, spectacular auroras
seem to dance high above. But the International
Space Station (ISS)
orbits at nearly the same height as many auroras,
sometimes passing
over them, and sometimes right through them. Still,
the auroral electron
and proton
streams pose no direct danger to the ISS.
In 2003, ISS Science Officer Don
Pettit captured the green aurora, pictured
above in a digitally sharpened image. From
orbit, Pettit
reported that changing auroras
appeared to crawl around like giant green amoebas.
Over 300 kilometers below, the Manicouagan
Impact Crater can be seen in northern Canada,
planet Earth.
APOD:
2003 August 9 - A Perseid Aurora
Explanation:
Just after the Moon
set but before the Sun
rose in the early morning hours of 2000 August 12,
meteors
pelted the Earth from the direction of the constellation Perseus,
while ions
pelted the Earth from the Sun.
The meteors
were expected as sub-sand grains long left behind by Comet
Swift-Tuttle annually create the Perseids
Meteor Shower. The aurorae
were unexpected, however, as electrons,
protons,
and heavier
ions raced out from a large Coronal
Mass Ejection that had occurred
just days before on the Sun. In the foreground is Hahn's Peak, an
extinct volcano in Colorado,
USA.
Note that this year’s Perseid meteor shower will peak on the evenings on Aug. 11 & Aug. 12. Although the moon will be bright this year, prominent meteors known as fireballs or bolides, will still be visible, and oftentimes, spectacular.
APOD:
2002 April 22 - Comet and Aurora Over Alaska
Explanation:
Can you spot the comet? Flowing across the frozen Alaskan
landscape is an easily visible, colorful aurora. Just to the lower
left, however, well in the background, is something harder to spot:
Comet
Ikeya-Zhang, the brightest comet of recent years.
Although the aurora
faded in minutes, the comet
is just now beginning
to fade. It remains just barely visible
without aid, however, before sunrise in the East. The comet is
actually a giant dirt-covered
snowball that spends most of its time in the outer
Solar
System -- to where it is now returns. The above
photograph was taken on March 20 when Comet
Ikeya-Zhang was near its brightest. Careful
inspection of the photo will uncover several other sky delights,
including the giant galaxy M31.
Tb1: Aurora over the Tetons shot by Ron Sprouse in 2004.
VaWalta2: Aurora over the Tetons shot by Walt Farmer from his driveway next to the Jackson Hole airport in 2001.