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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QUIET
SUN: Solar activity is very low.
WIth no sunspots producing strong flares, the sun's
x-ray output has flatlined.
Significant flares are unlikely this weekend.
SPIRAL
COMET TAIL: As Comet Lovejoy recedes
intact from its Dec. 16th close encounter with the
sun, researchers are pondering a mystery: What made
the comet's tail wiggle so wildly in transit through
the sun's atmosphere? The effect is clear in this
sequence of extreme UV images recorded by NASA's
STEREO-B spacecraft:
"Why the wiggles?" wonders
Karl Battams of the Naval Research Lab. "We're
not sure. There might be some kind of helical motion
going on. Perhaps we're seeing material in the tail
magnetically 'clinging' to coronal loops and moving
with them. [Coronal loops are huge loops of magnetism
that emerge from the sun's surface and thread the
sun's atmosphere.] There are other possibilities
too, and we will certainly investigate those!"
Battams notes that these images can
be combined with similar images from STEREO-A on
the other side of the sun to produce a three dimensional
picture. "When we pair these together, and
throw in the SDO images too, we should be able to
get an incredibly unique 3-D picture of how this
comet is reacting the the intense coronal heat and
magnetic loops. We are going to learn a lot."
AMATEUR
ASTRONOMERS TRACK LOVEJOY: Amateur
astronomers are finding themselves able to photograph
Comet Lovejoy as it emerges from the glare of the
sun. A team led by Czech astronomer Jan Ebr captured
this image at dawn on Dec. 17th:
Credit: Jakub Cerny,
Jan Ebr, Martin Jelinek, Petr Kubanek, Michael Prouza,
Michal Ringes
"We used a remotely-controlled
12-inch telescope in Malargue, Argentina,"
says Ebr. "The sun was below horizon at the
time we took the picture, but just barely. There
was only a 30 minute window between the rise of
the comet and that of the sun "
more images: from
Vincent Jacques of Breil-sur-Roya, France; from
Robert Lowton of Whaley Bridge, High Peak, United
Kingdom; from
Andrew Cooper of Mauna Kea, Hawai'i; from
Jim Werle of Las Vegas, Nevada;
Dec.
10th Total Lunar Eclipse Gallery
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
December 18, 2011 there were 1272
potentially hazardous asteroids.
Recent
& Upcoming Earth-asteroid encounters:
| Asteroid |
Date(UT) |
Miss
Distance |
Mag. |
Size |
| 2000 YA |
Dec 26 |
2.9 LD |
-- |
80 m |
| 2011 SL102 |
Dec 28 |
75.9 LD |
-- |
1.0 km |
| 2011 WS95 |
Dec 28 |
7.1 LD |
-- |
49 m |
| 1991 VK |
Jan 25 |
25.3 LD |
-- |
1.9 km |
| 433 Eros |
Jan 31 |
69.5 LD |
-- |
8.5 km |
| 2009 AV |
Feb 16 |
44.9 LD |
-- |
1.2 km |
| 2000 ET70 |
Feb 19 |
17.7 LD |
-- |
1.0 km |
| 2011 CP4 |
Feb 23 |
9.1 LD |
-- |
255 m |
| 2008 EJ85 |
Mar 6 |
9.1 LD |
-- |
44 m |
| 1999 RD32 |
Mar 14 |
57.9 LD |
-- |
2.3 km |
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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