METEORS DEFY EXPLANATION: The annual
Geminid meteor shower peaks this year on Dec. 13th
and 14th. Researchers don't fully understand the
Geminids, and new measurements, they say, make it
more mysterious than ever. Get the full
story from Science@NASA.
POPS OUT: Last night (Dec. 6th),
deep in western twilight, the crescent Moon eclipsed
(occulted) Mars over North America. "I was
perfectly placed to observe the event," says
Doug Zubenel of De Soto, Kansas, who caught Mars
popping out from behind the crescent. "It
happened right behind the
water tower of De Soto!"
BLAST: As predicted, the a "mega-filament"
of solar magnetism erupted on Dec. 6th, producing
a blast of epic proportions. NASA's Solar Dynamics
Observatory recorded the action as the 700,000-km
long structure lifted off the stellar surface and--snap!!--hurled
itself into space. Click on the arrow to play the
movie formats: 4
MB gif, 1
MB iPad, 0.5
MB iPhone, 1
MB still frame
The eruption produced a bright coronal
mass ejection (CME) observed by the STEREO-A spacecraft:
Earth was not in the line of fire; the cloud should
sail wide of our planet. Earth-effects might be
limited to pretty pictures.
more images: from
Stephen W. Ramsden of Atlanta, GA
SHADOW OF EARTH: Imagine stepping
out your front door and being swallowed up by the
vast dark shadow of an entire planet. Actually,
you've done it many times. The darkness you experience
after sunset is the shadow of Earth itself. (Think
about it.) If you happen to be outside right at
sunset, you can sometimes catch Earth's shadow rising
to extinquish the twilight. That's exactly what
happened to Andrew Greenwood yesterday in England's
Peak District National Park:
"I was climbing towards a hill
known as Shining Tor when I broke through the fog
into the most magical sunlit landscape," says
Greenwood. "With the clouds below me, the air
was crisp and ultra-transparent. It was at this
point that I noticed Earth's shadow climbing into
the ice-blue sky in the East. This spectacular vision
is sometimes called the 'Belt
of Venus.' Its contrast against the snow-covered
hills was breath-taking; I could not have wished
for a more memorable end to what was in fact my
more images: from
Börkur Hrólfsson of Gullfoss, Iceland.
2010 Aurora Gallery
[previous Novembers: 2009,
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
all the time.
December 7, 2010 there were 1167
potentially hazardous asteroids.
Notes: LD means "Lunar
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.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO is the most
advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather