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. |
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BRIGHT
CME: NASA twin STEREO spacecraft
observed a spectacular coronal mass ejection launched
from the vicinity of decaying sunspot 1176 on April
3rd around 0500 UT. The blast was not Earth directed.
Nevertheless, there is a slim chance that it deliver
a glancing blow to Earth's magnetic field on or
about April 6th. CME movies: STEREO-A,
STEREO-B.
AURORA
WATCH: A high-speed solar wind stream
is buffeting Earth's magnetic field and stirring
up auroras around the Arctic Circle. Steve Milner
sends this exposure from Fort St. John, British
Columbia, Canada:
"I took the picture just after
midnight on April 2nd," says Milner. "To
the naked eye, the display was pale, but a 20 second
exposure with my Canon D7000 revealed a panoply
of color."
High-latitude sky watchers should
remain alert
for auroras--even "pale" ones--as the
solar wind continues to blow.
NEW:
April
2011 Aurora Gallery
[previous Aprils: 2010,
2009, 2008,
2007,
2006,
2005,
2004, 2003,
2002]
SECRET
SPACE PLANE FLARES: The US Air Force's
X-37B
space plane is circling Earth and, although it is
on a classified mission with an officially unpublished
orbit, sky watchers have spotted
it. "I saw the X-37B from my home in Pasadena,
California, around sunrise on March 31st,"
reports Anthony Cook of the Griffith Observatory.
"The spacecraft's appearance was remarkable.
When overhead it was a little brighter than a 2nd
magnitude star with a slight yellow hue. Then it
flared. As the X-37B moved toward the horizon it
became silvery and brightened to around magnitude
-6, far outshining Venus below it." The flare
was presumably caused by sunlight glinting from
some flat surface on the shuttle-shaped spacecraft,
but no one can say for sure because it is
a classified mission. Ready for a secret flare of
your own? Space plane flyby preditions may be found
on the Simple Satellite Tracker
or on your cell
phone.
SATURN'S
RINGS SURGE IN BRIGHTNESS: This
Sunday, April 3rd, Saturn will be "at opposition"--that
is, opposite the sun in the skies of Earth. Whenever
this happens, Saturn's rings surge in brightness.
Why? Scroll down for the explanation; on the way,
inspect this photo taken by Paul Haese of South
Australia on March 30th:
"This is how Saturn looked through my 14-inch
telescope," says Haese. "With opposition
so close, the Seeliger effect is really starting
to show itself. The rings are much more spectacular
than in previous years."
The Seeliger
effect, also known as the opposition
effect, is what brightens the rings. Saturn's
rings are made of frozen chunks ranging in size
from dust to houses. Sunlight directly backscattered
from those ice particles causes the ring system
to shine even more than usual for a few days around
opposition. The exact mechanism involves shadow-hiding
and possibly coherent
backscattering.
To find Saturn, go outside at midnight and look
for a conspicuous yellow "star" in the
constellation Virgo. Even a small telescope will
show Saturn's brightening rings. [sky
map]
more images: from
Efrain Morales Rivera of Aguadilla, Puerto Rico;
from
Christopher Go of Cebu City, Philippines
