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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MEANWHILE
ON THE FARSIDE: For the past week,
all eyes have been on the Earth-side of the sun,
where sunspots 1158 and 1161-1162 have unleashed
some of the strongest flares in years. Meanwhile,
the farside of the sun has been busy, too. Regard
this movie from NASA's STEREO-B probe covering
the first 20 hours of Feb. 19th. A huge active region
is transiting the farside and crackling with flares;
it will turn toward Earth in about a week. What's
the best way to keep track of the sun's farside?
Download 3D Sun for
the iPhone and iPad. (Note: An Android version will
soon be available.)
WEEKEND
AURORAS: On Saturday night, Feb.
19th, the interplanetary magnetic field (IMF)
near Earth tipped south. This opened a crack in
Earth's magnetosphere; solar wind poured in and
fueled a display of Northern Lights around the Arctic
Circle:
"It was a truly wonderful night," says
photographer Andy Keen of Inari, FInland. "We
were out until 2am taking pictures of auroras dancing
over the moonlit landscape."
Readers, would you like to see scenes like this
with your own eyes? Keen is willing to take you
on an aurora tour. Click
here for details.
UPDATED: February
2011 Aurora Photo Gallery
[previous Februaries: 2010,
2009,
2008,
2007, 2006,
2004, 2003,
2002]
FLICKERING
SOLAR SAIL: NASA has joined forces
with Spaceweather.com to stage a solar
sail photography competition. Top prize: $500.
Peter Rosen hasn't won yet, but with this movie
of NanoSail-D, he has definitely entered the
contest:
Photo details:
Canon EOS 5D Mk II, 85/1.2 lens @ 1.2, 55 one-sec
exposures at ISO 3200.
Not to be confused with the airliner at the top
of the photo, NanoSail-D is the star-like object
below denoted by a cross. Watch the movie again
and note how the sail flickers in the inset circle.
Rosen describes what happened: "I photographed
NanoSail-D from Stockholm, Sweden, on Feb. 4th.
The sail was very low on the horizon, but I was
able to catch it using my Canon
EOS 5D digital camera. I estimate its magnitude
between 6 and 7."
"There are many other satellites in the field
of view and some airplanes coming in for landing
at the local airport," he continues. "NanoSail-D
behaves very differently from other satellites as
its visibility seems to pulsate in short flashes
sometimes several per second. This
image zooms in on the phenomenon. I wonder if
it due to small changes in the sail's direction
and thus reflectivity?"
Indeed, sunlight is almost certainly glinting off
the sail's reflective fabric. Researchers believe
these flickers could, from time to time, develop
into spectacular
flares, outshining the brightest stars and perhaps
even exceeding the luminosity of Iridium flares.
At the moment, these flares are unpredictable because
the sail's orientation is not known precisely enough
to forecast sun-glints. The only way to catch one
is to go outside and look.
NanoSail-D flyby times: on
the web, on
your cell phone.
