Metallic photos of the sun by renowned photographer Greg Piepol bring together the best of art and science. Buy one or a whole set. They make a stellar gift.
METEOR SHOWER: Earth is approaching
the debris field of ancient Comet Thatcher, source
of the annual Lyrid
meteor shower. Forecasters expect the shower
to peak on April 21-22; a nearly-new moon on those
dates will provide perfect dark-sky conditions for
meteor watching. Usually the shower is mild (10-20
meteors per hour) but unmapped filaments of dust
in the comet's tail sometimes trigger outbursts
10 times stronger. [video]
EXPLOSION (UPDATED): Magnetic fields
on the sun's northeastern limb erupted around 17:45
UT on April 16th, producing one of the most visually-spectacular
explosions in years. NASA's Solar Dynamics Observatory
(SDO) recorded the blast at extreme ultraviolet
The explosion, which registered M1.7
on the Richter
Scale of solar flares, was not Earth-directed,
but it did hurl a CME into space. Analysts at the
Goddard Space Weather Lab have analyzed the
trajectory of the cloud and found that it will
hit NASA's STEREO-B spacecraft, the Spitzer space
telescope, and the rover
Curiosity en route to Mars. Planets Venus and
Mars could also receive a glancing blow.
Using data from SDO, Steele Hill of
NASA's Goddard Space Flight Center assembled a must-see
movie of the event. It shows the explosion unfolding
at 304Å, a wavelength which traces plasma with a
temperature around 80,000 K.
Coverage of the blast was not limited
to space telescopes. Amateur astronomers saw it,
too. Jim Lafferty sends this picture from his backyard
observatory in Redlands, California:
"Yesterday's prominence on the
sun's eastern limb was was one of the largest in
years---short lived, it was mostly gone in a few
hours," says Lafferty. "It was a wonderful
sight in the eyepiece and in the camera!"
more images: from
Vahan Yeterian of Lompoc California; from
John Minnerath of Crowheart, Wyoming; from
John Stetson of Falmouth, Maine; from
Thomas Ashcraft of New Mexico;
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
all the time.
April 17, 2012 there were 1287
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.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO
is the most advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather