Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift. |
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CHINESE
SPACE STATION: Last Thursday, China
launched an experimental space station named Tiangong-1
(Heavenly Palace-1). The 8.5-ton module, about the
size of a railroad car, will remain in orbit for
two years as Chinese spacecraft perform rendevous
and docking maneuvers, and Chinese astronauts visit
for weeks at a time--all good practice for a larger
outpost in the future. Check Spaceweather's Satellite
Tracker for sighting opportunities. You can
also turn your smartphone into a Tiangong-1 tracker
by downloading the Simple
Flybys app.
COMET
AND CME: A comet discovered by amateur
astronomers on Friday, Sept. 30th, disintegrated
in spectacular fashion the very next day when it
plunged into the sun. The Solar and Heliospheric
Observatory recorded the comet's last hours. The
end was punctuated by an unexpected explosion:
Watch the movie again.
The timing of the CME so soon after the comet dove
into the sun suggests a link. But what? There is
no known mechanism for comets to trigger solar explosions.
Before 2011 most solar physicists would have discounted
the events of Oct. 1st as pure coincidence--and
pure coincidence is still the most likely explanation.
Earlier this year, however, the Solar Dynamics Observatory
(SDO) watched another sungrazer disintegrate in
the sun's atmosphere. On July
5, 2011, the unnamed comet appeared to interact
with plasma and magnetic fields in its surroundings
as it
fell apart. Could a puny comet cause a magnetic
instability that might propagate and blossom into
a impressive CME? The question is not so crazy as
it once seemed to be.
DOUBLE
ERUPTION: On October 1st around
10:17 UT, widely-spaced sunspots 1302 and 1305 erupted
in quick succession, revealing a long-distance entanglement
which was not obvious before. NASA's Solar Dynamics
Observatory (SDO) recorded the double blast:
Since it was launched in 2010, SDO
has observed many "entangled eruptions."
Active regions far apart but linked by magnetic
fields can explode one after another, with disturbances
spreading around the stellar surface domino-style.
Saturday's eruption appears to be the latest example.
The part of the eruption centered
on sunspot 1305 hurled a coronal mass ejection toward
Earth. The relatively slow-moving (500 km/s) cloud
is expected to reach our planet on Oct. 4th or 5th,
possibly causing geomagnetic storms when it arrives.
High-latitude sky watchers should be alert for auroras.
Geomagnetic storm
alerts: text,
voice.
September
2011 Aurora Gallery
[previous Septembers: 2010,
2009, 2008,
2007,
2006,
2005,
2004]
TODAY'S
BONUS SHOTS: Winged
Sunspot from Deepak Dogra of New Delhi, India;
Spotted
Sunset from Claudio Balella of the San Marino
Republic in Italy; The
Sun in Motion from Jerome Grenier of Paris,
France; Moonlit
Meteor from Paul Martini of Joshua Tree, California;
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
October 3, 2011 there were 1250
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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the
underlying science of space weather |
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for
out-of-this-world printing and graphics |
