AURORA ALERTS: Did you miss the Northern Lights? Next time
get a wake-up call from Space
Weather PHONE |
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GROUND
CURRENTS IN NORWAY: Rob Stammes
operates a geomagnetic observatory in Lofoten, Norway,
and he is measuring strong
ground currents on Sept. 8th: "Magnetic
activity began around 15.00 UT," says Stammes.
"The ground currents are much stronger than
last night when the auroras were bright. If this
continues, we might see an even better display this
evening."
EARTH
DODGES ANOTHER BULLET: Just as
sunspot 1105 was turning away from Earth on Sept.
8th, the active region erupted, producing a C3-class
solar flare (peak @ 2330 UT) and a fantastic prominence.
Here is a snapshot from the Solar Dynamics Observatory:
The eruption also hurled a bright coronal mass
ejection (CME) into space: SOHO
movie. The expanding cloud is heading into a
part of the solar system not currently occupied
by any planet--it's going to miss everything, including
Earth. If such a CME did hit Earth's magnetic field,
it would probably trigger strong geomagnetic storms.
Maybe next time...
Update #1: Two new movies of the
eruption are available from the Solar Dynamics Observatory--a
big picture
view in black-and-white and a spectacular
close-up in three extreme UV colors.
Update #2: NASA's STEREO-Ahead
spacecraft is stationed almost directly above sunspot
1105. A first-look
movie shows a shadowy "solar tsunami"
wave racing away from the blast site.
PURPLE
AURORAS: Auroras are dancing around
the Arctic Circle and some of them are purple. This
is how the sky looked on Sept. 8th over Bø, Norway:
"It's not often I get to see
purple auroras," says photographer Øystein
Lunde Ingvaldsen. "This was truly a fantastic
sight!"
Auroras get their
colors from specific atoms and molecules in
Earth's atmosphere. Green comes from oxygen molecules
excited by geomagnetic activity. Purple, on the
other hand, is usually a mixture of red and blue
emissions from molecular nitrogen. O2
and N2 were both revved up in Norway
last night!
More purple is possible tonight as
a solar wind stream continues to buffet Earth's
magnetic field. High-latitude sky watchers should
remain alert
for auroras.
NEW:
Sept.
2010 Northern Lights Gallery
[previous Septembers: 2009,
2008,
2007,
2006,
2005,
2004,
2002,
2001,
2000]
Potentially
Hazardous Asteroids (
PHAs)
are space rocks larger than approximately 100m that can come
closer to Earth than 0.05 AU. None of the known PHAs is on
a collision course with our planet, although astronomers are
finding
new
ones all the time.
On September 9, 2010 there were 1144 potentially hazardous asteroids.
Notes: LD means "Lunar
Distance."
1 LD = 384,401 km, the distance between Earth and the Moon.
1 LD also equals 0.00256 AU. MAG is the visual magnitude
of the asteroid on the date of closest approach.
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The
official U.S. government space weather bureau |
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The
first place to look for information about sundogs,
pillars, rainbows and related phenomena. |
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Researchers
call it a "Hubble for the sun." SDO is the most
advanced solar observatory ever. |
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3D
views of the sun from NASA's Solar and Terrestrial
Relations Observatory |
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Realtime
and archival images of the Sun from SOHO. |
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from
the NOAA Space Environment Center |
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from
the National Solar Data Analysis Center |
