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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CHANCE OF FLARES:
A pair of Earth-facing sunspots,
AR1917 and AR1918, have 'beta-gamma' magnetic fields
that harbor energy for moderately strong solar flares.
Any eruptions from the duo in the days ahead would
likely be geoeffective. NOAA forecasters estimate
a 25% chance of M-class
flares during the next 24 hours.
Solar flare alerts:
text,
voice
CHINA LANDS ON THE
MOON: Move over USA and Russia.
China has joined the club of nations that has landed
on the Moon. On Saturday, Dec. 14th, at 9:41 p.m.
Beijing local time, China's Chang’e-3 lunar lander
touched down in Sinus Iridum, the Bay of Rainbows.
Hours later, a lunar rover named the Jade Rabbit
("Yutu" in Mandarin Chinese) emerged for
a historic mission of exploration:
Click
to view more pictures from the lunar surface
The six-wheeled, 260-lb rover is equipped
with a Chinese-made nuclear battery expected to
last for more than 30 years. The rover also has
expandable solar arrays to absorb the sun’s energy
during the day and retract at night to cover and
protect equipment from temperatures of minus 170
degrees Celsius. Onboard sensors include a ground-probing
radar, cameras, and a soil sampler.
The United States has not performed a soft landing
on the Moon since 1972 when Apollo
17 delivered astronauts Gene Cernan and Jack
Schmitt to the Taurus-Littrow valley. The former
USSR last did it in 1976 with the sample return
mission Luna
24.
Now, after a surprising 37-year gap in lunar ground
exploration, China has started making its own tracks
in the moondust. Congratulations to the people of
China for their successful landing and lunar ambitions.
GEMINIDS SUBSIDING:
The Geminid meteor shower is subsiding
now as Earth exits a stream of debris from rock
comet 3200 Phaethon. Preliminary counts by the
International Meteor Organization suggest that the
shower peaked on Dec. 14th with more than 100 meteors
per hour. Most observers saw only a fraction of
that number, however, as bright moonlight washed
out many faint Geminids. Fortunately, the shower
was rich in fireballs like this one:
Amateur astronomer Thomas Ashcraft
recorded the fireball using an all-sky camera and
a 61 MHz radio receiver. Watch
the movie again and turn up the volume. The
soundtrack is the echo of a distant TV transmission
bouncing off the ionized trail of the disintegrating
meteoroid. "By listening to the radio echoes,
I could tell there was a strong display of meteors
all through the night," says Ashcraft. "We
were lucky that some Geminid fireballs appeared
through holes in our cloudy skies."
The shower is subsiding, but it's
not over. Earth will be inside the debris stream
of 3200 Phaethon for some days to come. Look west
during the magic
hour before sunrise, and you still could see
dozens of Geminids between now and Dec. 16th.
Realtime
Meteor Photo Gallery
EDGE OF SPACE CHRISTMAS
CARDS: What do you give to the
sky watcher who has everything? How about a Christmas
card from the Edge of Space? For only $49.95, the
students of Earth
to Sky Calculus will fly your holiday greeting
or favorite picture to the top of Earth's atmosphere,
photograph it, and return the snapshot in time for
the holidays. It's a unique gift! The group has
previously flown cupcakes,
shoes,
US
presidents, ad
banners and telescopes.
This holiday magic is performed using suborbital
helium balloons. Contact Dr.
Tony Phillips for more information.
Realtime
Space Weather Photo Gallery
Realtime
Aurora Photo Gallery
Comet
ISON Photo Gallery
Realtime
Comet 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. 15, 2013, the network reported
52 fireballs.
( 30 Geminids, 20 sporadics, 2 December
Leonis Minorids)
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 16, 2013 there were 1446
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 |
