AURORA ALERTS: Did you miss the Northern Lights? Next time
get a wake-up call from Space
Weather PHONE |
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INTERNATIONAL
SPACE WEATHER INITIATIVE: Prompted
by a recent increase in solar activity, more than
a hundred researchers and government officials are
converging on Helwan, Egypt, this week to discuss
the peril of storms from the sun. Get the full
story from Science@NASA.
COMET
OUTBURST: Comet Ikeya-Murakami
(C/2010 V1) is definitely undergoing an outburst
event. Italian astronomers Ernesto Guido and Giovanni
Sostero assembled the following animation from images
they obtained between Nov. 4th and Nov 9th:
The sequence clearly shows an explosion
in progress. "Only Nov. 7th is missing,"
they say, "because of rare cloudy skies over
New Mexico, where the remotely-controlled telescope
we used is located."
Another New Mexico observer, Leonid
Elenin, estimates the size of comet's expanding
atmosphere as 4x6 arcminutes. "There is also
some
evidence of two symmetrical jets emerging from
the nucleus of the comet," he says.
The behavior of this comet reminds many onlookers
of exploding
Comet Holmes in 2007. Researchers believe Holmes
exploded when an icy cavern in the comet's nucleus
collapsed. Perhaps something similar has happened
to Comet Ikeya-Murakami. The icy visitor from the
outer solar system made its closest approach to
the Sun in late October, so it has just received
a dose of solar heating that could trigger such
an event.
Amateur astronomers are encouraged to monitor developments.
Various reports put the brightness of the comet
between 7th and 9th magnitude, invisible to the
naked eye but an easy target for telescopes such
as the
Comet Hunter. It's easy to find, too, little
more than a degree from Saturn in the eastern sky
before dawn. Set your alarm and happy hunting! [Sky
maps: Nov.
9, 10,
11]
[3D
orbit] [ephemeris]
more images: from
Joseph Brimacombe using a robotic telescope
in New Mexico (Nov.8); from
Gil Esquerdo of Whipple Observatory, Mt. Hopkins,
Arizona (Nov. 8); from
Tenho Tuomi of Lucky Lake, SK, Canada (Nov.
7); from
Gregg Ruppel of Ellisville, Missouri (Nov. 7);
from
Feys Filip of Crete, Greece (Nov. 6); from
Gregg Ruppel of Ellisville, Missouri (Nov. 6);
from
Gregg Ruppel of Ellisville, Missouri (Nov. 5);
from
Luca Buzzi of the G.V. Schiaparelli Astronomical
Observatory in Varese, Italy (Nov. 4);
RELUCTANT
SUNRISE: On Nov. 7th, the sunrise
over Grand Marais, Minnesota, could only be described
as reluctant. "The sun just wanted to stick
to Lake Superior," says Bryan Hansel who snapped
this picture:
Photo details: Nikon
D200, Nikkor 300 f/4, 1.4x multiplier, 100 ISO,
f/16, 1/640.
"I know the feeling," he says. "I
just wanted to stick to my bed, but the lake and
sunrise called, and I'm glad I answered!"
This is an excellent example of a sunrise mirage.
The great volume of water in Lake Superior holds
a lot of heat. During the long cold night of Nov.6th,
air nestled against the lake's surface was kept
relatively warm. By sunrise on Nov. 7th, a temperature
inversion had formed, setting the stage for
a distorted "sticky sun."
more images: from
Keith Aaron of Virginia Beach, Virginia; from
Lyle Anderson of Duluth, Minnesota; from
Robert of San Francisco, California; from
Mila Zinkova of San Francisco, California
October
2010 Aurora Gallery
[previous Octobers: 2009,
2008,
2007,
2006,
2004, 2003,
2002,
2001]
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
November 9, 2010 there were 1164potentially
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 |
