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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CME AND RADIATION
STORM: A solar radiation storm is
in
progress on May 22nd following an M5-class explosion
on the sun's western limb. The source of the flare,
which peaked at 1332 UT, was departing sunspot AR1745.
SOHO coronagraphs observed a magnificent CME emerging
from the blast site:
Play the movie again.
The speckles dancing across the image are caused
by high-energy solar protons striking the CCD camera
in SOHO's coronagraph.
Those protons were guided toward Earth by magnetic
field lines that connect our planet to the blast
site. The rain of protons is what forecasters mean
by a "radiation storm." This storm ranks
S2 on NOAA
storm scales.
Update (May 22 @ 5:30 PDT):
Although the explosion was not squarely Earth-directed,
the CME will likely be geoeffective. The expanding
cloud appears set to deliver a glancing blow to
Earth's magnetic field on May 24th around 1200 UT.
According to NOAA forecast models, the impact will
more than double the solar wind plasma density around
Earth and boost the solar wind speed to ~600 km/s.
High-latitude sky watchers should be alert for auroras.
Aurora alerts:
text,
voice.
Realtime
Space Weather Photo Gallery
THE SHOW BEGINS:
The long-awaited sunset
sky show of May 2013 is beginning. In only a
few days, Venus, Jupiter and Mercury will form a
tight triangle in the western sky, visible to the
unaided eye around the world. Last night, Fred Espenak
of Portal, Arizona, photographed the trio in the
early stages of convergence:
"The three planets were easily
visible to the naked eye in spite of the bright
twilight glow," says Espanel. "Mercury
should be even easier to spot in the coming days
as it climbs higher into the sky. "
In the nights ahead, the line of planets
will collapse to form a triangle. At closest approach
on May 26th, they will fit within a circle less
than 3o wide. Start watching tonight--it's
a great way to end the day. [full
story] [video]
Realtime
Planet Photo Gallery
A BIG ASTEROID APPROACHES:
Near-Earth asteroid 1998
QE2 is approaching the Earth-Moon system for
a flyby on May 31st. There's no danger of a collision;
at closest approach the asteroid will be 3.6 million
miles away. Even at that distance, however, the
1.7-mile-wide space rock will be an easy target
for mid-sized backyard telescopes. Using a 14-inch
Celestron, Alberto Quijano Vodniza of Narino, Colombia
took this picture of 1998 QE2 on May 17th:
The sunlit side of the asteroid will
turn more squarely toward Earth during the first
week of June. At that time it will reach a maximum
brightness of 11th magnitude.
NASA radars will be monitoring the
flyby, too. "Asteroid 1998 QE2 will be an outstanding
radar imaging target at Goldstone and Arecibo and
we expect to obtain a series of high-resolution
images that could reveal a wealth of surface features,"
says
radar astronomer Lance Benner of JPL. "Whenever
an asteroid approaches this closely, it provides
an important scientific opportunity to study it
in detail to understand its size, shape, rotation,
surface features, and what they can tell us about
its origin."
Stay tuned for updates and observing
tips.
Realtime
Aurora Photo Gallery
Realtime
Comet Photo Gallery
Realtime
Noctilucent Cloud Photo Gallery
[previous years: 2003,
2004,
2005,
2006,
2007,
2008,
2009,
2011]
