When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms. |
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HERE COME THE GEMINIDS:
Earth is entering a stream of debris
from rock
comet 3200 Phaethon, source of the annual Geminid
meteor shower. Forecasters expect the shower to
peak on Dec. 13-14 with as many as 120 meteors per
hour. Lunar interference will be a problem, as glare
from the nearly-full Moon reduces the number of
visible meteors 2- to 5-fold. You can listen to
radar echoes from the Geminids, unaffected by moonlight,
on Space
Weather Radio. Also, tune into NASA's live
web chat about the Geminids on Friday the 13th
beginning at 11 pm EST.
COMET ISON UPDATE:
Later this month, NASA plans to
point the Hubble Space Telescope at Comet ISON to
see if anything remains after the comet's death
plunge through the sun's atmosphere on Nov.
28th. Note to Hubble: Don't expect to see much.
Amateur astronomers are already searching the comet's
position and setting hard limits on the brightness
of any remains. Consider this image taken on Dec.
8th by Eric Allen of the Observatoire du Cégep de
Trois-Rivières in Champlain, Québec:
The position of the comet--had it
survived--is circled. "I unfortunately have
to say that there is nothing down to about magnitude
+16.5, not even a small condensation," says
Allen. More information about Allen's observing
techniques and image processing may be found here.
As Karl Battams of the Naval Research
Lab comments in his
blog on the Comet ISON Observing Campaign web
site: "The evidence appears strong that at
some point approaching perihelion Comet ISON likely
began to completely fall apart. What remains of
ISON now is going to be either just a cloud of dust,
or perhaps a few very depleted chunks of nucleus.
Either way, it's not going to flare up at this point
and we should assume the comet's show is over."
Comet
ISON Photo Gallery
COMET LOVEJOY'S ACTIVE
TAIL: Amateur astronomers around
the northern hemisphere are reporting activity in
the tail of naked-eye Comet Lovejoy (C/2013 R1).
In Nagano, Japan, astrophotographer Kouji Ohnishi
could see big changes in less than an hour of monitoring:
Michael Jäger saw the same "disconnection
event" from his observatory in Masenberg,
Austria, on Dec. 5th. The disturbance could be caused
by a gust of solar wind or perhaps an episode of
vigorous outgassing in the comet's core.
Comet Lovejoy is now about as bright
as a 4th magnitude star. It is visible to the unaided
eye from the countryside and is an easy target for
backyard telescopes even in urban areas. Monitoring
is encouraged. Comet Lovejoy rises in the east just
before the morning sun. Sky maps:
Dec. 7,
8, 9.
Realtime
Comet Photo Gallery
Realtime
Aurora Photo Gallery
Realtime
Space Weather Photo Gallery
Every night, a network
of NASA all-sky
cameras scans the skies above the United States
for meteoritic fireballs. Automated software maintained
by NASA's Meteoroid Environment Office calculates
their orbits, velocity, penetration depth in Earth's
atmosphere and many other characteristics. Daily results
are presented here on Spaceweather.com.
On Dec. 9, 2013, the network reported
22 fireballs.
(20 sporadics, 1 Geminid, 1 sigma
Hydrid)
In this diagram of the inner solar
system, all of the fireball orbits intersect at
a single point--Earth. The orbits are color-coded
by velocity, from slow (red) to fast (blue). [Larger
image] [movies]
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 10, 2013 there were
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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