Emerging sunspot 1105 erupted on
Sept. 3rd at 1520 UT, producing a B2-class solar flare. The nominally-minor blast blew a bubble in the
sun's atmosphere more than 50,000 km wide. The action unfolds
in this extreme ultraviolet movie from the Solar Dynamics
Observatory:

. The bubble is the dark crescent-shaped void
expanding to the upper left of the sunspot's bright magnetic
canopy. Several copies of our entire planet Earth could fit
inside that volume with room to spare. What seems huge by
Earth-standards, however, is minuscule on the sun. At maximum,
the bubble occupied a volume less than 0.003% of the total
solar globe.

more images:from
Michael Borman of Evansville, Indiana; from
Cai-Uso Wohler of Bispingen, Germany; from
Jérôme Grenier of Paris France; from
Robert Arnold of Isle of Skye, Scotland

iPHONE VS ANDROID! Actually, it doesn't matter which phone you carry. Our cool, new app turns both smartphones into field-tested satellite trackers. Learn more.

BLOWING
BUBBLES: Emerging sunspot 1105 erupted today
at 1520 UT, producing a B2-class solar flare. The minor blast
blew a bubble in the sun's atmosphere more than 50,000 km
wide. The action unfolds in this extreme ultraviolet movie
from the Solar Dynamics Observatory:

Watch
it again. The bubble is the dark crescent-shaped void
expanding to the upper left of the sunspot's bright magnetic
canopy. Several copies of our entire planet Earth could fit
inside that volume with room to spare. What seems huge by
Earth-standards, however, is miniscule on the sun. At maximum,
the bubble occupied a volume less than 0.003% of the total
solar globe. It's all relative,
after all.

Stay tuned for bigger bubbles as sunspot 1105
continues to grow.

iPHONE VS ANDROID! Actually, it doesn't matter which phone you carry. Our cool, new app turns both smartphones into field-tested satellite trackers. Learn more.

On Sept. 1st at 21:55
UT, NASA's STEREO-A spacecraft has detected a strong solar
flare on the far side of the sun. The blast produced a
flash of extreme UV radiation and hurled a coronal mass
ejection (CME) over the sun's southwestern limb:

The cloud is heading in the general direction
of Saturn and poses no threat to Earth. Like a reported on Aug. 31st, this event was centered on
old sunspot group 1100. Solar rotation will turn the active
region back toward Earth for possible geoeffective action
in about 7 to 9 days. Stay tuned!

VIRTUAL
REALITY PARHELIC CIRCLE: A parhelic
circle is an unforgettable sight. Thin and pale, it circles
the zenith in a majestic arc, always keeping the same distance
above the horizon. "I've been looking for a parhelic
circle for more than 13 years," says photographer Laurent
Laveder of Pluguffan, France. "Yesterday I finally
saw one." He rushed for his camera and quickly snapped
enough pictures to assemble a complete 360^o zenith-to-horizon
composite view of the phenomenon. Click on the image below
to experience the VR
parhelic circle:

Parhelic circles are caused by sunlight reflecting from the
vertical faces of ice crystals--millions of them floating
in thin cirrus clouds spread almost evenly across the wide
blue sky. As Les Cowley notes in his authoritative
web page on the subject, "the parhelic circle appears
simple yet more ray paths contribute to it than in any other
halo. Some are very intricate."

A striking aspect of the parhelic circle is its dual personality.
At the same time it appears both circular and straight. "These
two pictures (,
2) illustrate
the effect," says Laveder. More images may be found here.

NASA
MISSION TO TOUCH THE SUN: NASA's daring plan
to visit the sun took a giant leap forward today with the
selection of five key science investigations for the Solar
Probe+ spacecraft. Get the full
story from Science@NASA.

AURORA ALERTS: Did you miss the Northern Lights? Next time get a wake-up call from Space Weather PHONE

AURORA
SURPRISE: "Wow, what a surprise,"
reports
P-M Hedén of Sweden. "Last night, I was out photographing
the moonlit landscape north of Norrtälje when the aurora
borealis appeared." There was no geomagnetic storm.
A slight elevation in the solar wind speed overnight was sufficient
to spark the display.

FARSIDE
ACTIVITY CONTINUES: For the second day in
a row, NASA's STEREO-A spacecraft has detected a strong solar
flare on the far side of the sun. Click
here to view the flash of extreme UV radiation, which
peaked at 21:55 UT on Sept. 1st. The blast also hurled a coronal
mass ejection (CME) over the sun's southwestern limb:

See the cloud expand:0.6
MB gif animation

The cloud is heading in the general direction
of Saturn and poses no threat to Earth. Like the similar
flare reported yesterday, today's event was centered on
old sunspot group 1100. Solar rotation will turn this active
region back toward Earth for possible geoeffective action
in about 7 to 9 days. Stay tuned!

For four hours on August
30th, the atmosphere over Exmouth, Western Australia, settled
into a state of rare, crystal-clear transparency -- and it
did so directly above the telescope of world-famous astrophotographer
Anthony Wesley. The result was

For four hours on August
30th, the atmosphere over Australia settled into a state of
rare, crystal-clear transparency -- and it did so directly
above the observatory of world-famous astrophotographer Anthony
Wesley. The result was

FARSIDE
FLARE: The sun is not so quiet after all.
On Aug. 31 at 2055 UT, NASA's STEREO-A spacecraft observed
a strong solar flare on the far side of the sun. The flash
of electromagnetic radiation briefly saturated several pixels
in the spacecraft's extreme UV camera:

Click on the
image to launch a 0.7 MB gif animation

Earth-orbiting satellites did not detect this
flare at all. The entire body of the sun shielded us from
the radiation. Only STEREO-A, hovering over the farside of
the sun, was able to observe the event.

The source of the blast appears to be old sunspot
1100. Solar rotation will turn this active region back toward
Earth for possible geoeffective action in about 8 days. Stay
tuned.