| 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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ROCKET LAUNCH FOILED BY SOLAR ACTIVITY: Orbital
Sciences Corp. scrubbed today's launch of their Antares supply rocket
to the International Space Station in response to an ongoing solar
radiation storm, described below. A launch at 1:10 p.m. EST Thursday
is possible if the storm subsides. [ more]
STORMY SPACE WEATHER:
Giant sunspot AR1944 is directly
facing Earth and crackling with solar flares. Yesterday,
Jan. 7th, an X1-class
explosion in the sunspot's magnetic canopy hurled
a CME in our direction. Sky watchers
shoud be alert for auroras on Jan. 9th when the
cloud arrives. NOAA forecasters estimate
a 60% chance of strong geomagnetic storms. Aurora
alerts: text,
voice.
The X1-flare that hurled the CME toward
Earth also accelerated a swarm of high-energy protons
in our direction. Effects of the proton fusillade
are visible in this Jan. 7th coronagraph movie from
the Solar and Heliospheric Observatory (SOHO):
The "snow" in this
movie is caused by solar protons striking the
spacecraft's CCD camera. A veritable blizzard of
speckles develops as the CME emerges into full view.
Indeed, many of the protons are accelerated by shock
waves at the forefront of the expanding cloud.
This ongoing
radiation storm ranks S2
on NOAA storm scales. It is rich in "hard"
protons with more than 100 MeV of energy, which
accounts for the snowiness of the SOHO coronagraph
images. According to NOAA, "passengers and
crew in high-flying aircraft at high latitudes may
be exposed to elevated radiation risk" during
such a storm.
The source of all this activity is
AR1944, one of the biggest sunspots of the past
decade. The sprawling active region is more than
200,000 km wide and contains dozens of dark cores.
Its primary core, all by itself, is large enough
to swallow Earth three times over. To set the scale
of the behemoth, Karzaman Ahmad inserted a picture
of Earth in the corner of this picture he took on
Jan. 7th from the Langkawi National Observatory
in Malaysia:
More flares are in the offing. The
sunspot has an unstable 'beta-gamma-delta' magnetic
field that is likely to erupt again today. NOAA
forecasters estimate an 80% chance of M-class
flares and a 50% chance of X-flares
on Jan. 8th.
Solar flare alerts:
text,
voice.
VENUS, THE CRESCENT
PLANET: Venus is turning its night
side toward Earth as it approaches inferior solar
conjunction on Jan. 11th. Less than 1% of Venus's
sunlit hemisphere is now facing us, which means
the planet looks like a razor-thin crescent. If
you have a GOTO telescope, command it to slew to
Venus. It's visible even in broad daylight:
Shahrin Ahmad of Sri Damansara, Malaysia,
took the picture on Jan. 6th using a 4.5 inch telescope.
"As Venus gets closer to the sun, it gets thinner
everyday!" says Ahmad. "So far, this is
the thinnest Venus I've managed to photograph--a
mere 9.5o from the sun and just 1.3%
illuminated!"
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 Jan. 7, 2014, the network reported 30 fireballs.
(29 sporadics, 1 Quadrantid)
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]
On Jan. 6, 2014, the network reported 7 fireballs.
(6 sporadics, 1 alpha 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
January 8, 2014 there were 1450
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.
 end quote from:
spaceweather.com/ |
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