Don't just watch shooting stars. Wear them! Authentic meteorite jewelry for Christmas is now available in the SpaceWeather Store. |
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NIGHT
AFTER CHRISTMAS SKY SHOW: When the
sun goes down tonight, step outside and look west.
Venus and the crescent Moon have gathered together
for a lovely night-after-Christmas conjunction in
the sunset sky. Science@NASA has the full
story.
CMEs
TARGET EARTH, MARS: The odds of
a geomagnetic storm on Dec. 28th are improving with
the launch of two CMEs toward Earth in less than
24 hours. NASA's STEREO-B spacecraft photographed
this one on Dec. 26th:
According to a
forecast track prepared by analysts at the Goddard
Space Weather Lab, the cloud should squarely strike
Earth's magnetic field on Dec. 28th at 20:22 UT
(+/- 7 hours). Another CME could deliver a glancing
blow a few hours earlier on the same date. The double
impact is expected to spark mild-to-moderate geomagnetic
storms at high latitudes. Aurora
alerts: text,
voice.
Mars is also in the line of fire.
The first of the two CMEs is squarely directed toward
the Red Planet--estimated time of arrival: Dec.
30th at 1800 UT. Using onboard radiation sensors,
NASA's Curiosity rover might be able to sense
the CME when it passes the rover's spacecraft
en route to Mars.
BEAUTIFUL
BLAST: After three years of deep
quiet, the sun woke up in 2011. Sunspots and solar
flares became commonplace again as long-awaited
Solar Cycle 24 got
underway. One of the most beautiful eruptions
of the young solar cycle occured just this past
weekend. Rogerio Marcon of Campinas SP Brasil photographed
the blast on Christmas Eve:
"I made a time-lapse
video of the eruption," says Marcon. "What
a wonderful Christmas present." While Marcon
was recording the event from Earth, NASA's Solar
Dynamics Observatory was doing the same from Earth-orbit.
It was beautiful
up there, too.
This explosion was not Earth-directed.
Next time, however, could be different. The source
of the blast, sunspot 1386, is turning toward Earth,
increasing the chances of a geoeffective flare in
the days ahead. Solar
Flare alerts: text,
voice.
more images: from
Philippe Roucheux of Joigny, Bourgogne, France
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 26, 2011 there were 1272
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 |
