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APPROACHING COMET:
Comet Lulin (C/2007 N3) is swinging around
the sun and approaching Earth for a 38-million-mile close encounter
in late February. The comet is not yet visible to the naked eye,
but it is putting on a nice show for backyard telescopes. Check
the gallery for photos and
observing tips.
BIG MOONLIGHT:
During the weekend, did you have trouble sleeping? It was probably
the moonlight. The full Moon of Jan. 10th and 11th was the biggest
and the brightest of the year. Marek
Nikodem caught it rising over Szubin, Poland, on Saturday night:
"The moonrise was a wonderful and beautiful moment,"
he says. "I photographed the event using my Nikon
D50."
Astronomers call this a "perigee Moon" because it occurred
at perigee,
the side of the Moon's elliptical orbit closest to Earth. Those
moments of wakefulness you may have experienced were caused by an
Earth-Moon distance as much as 50,000 km less than usual. The next
perigee Moon: Jan. 30, 2010. That's a doubly special
date because not only will the Moon be a perigee Moon, but also
a Blue Moon (the second full Moon in a calendar month). Mark your
calendar!
more images: from
Brandon Brown of Red Deer, Alberta, Canada; from
Richard Saunders of Modjesta Peak, California; from
Anthony Arrigo of Park City, Utah; from
Jim Saueressig of Burlington, Kansas; from
Serdar Hepgul of Istanbul, Turkey; from
Serdar Hepgul of Istanbul, Turkey; from
Luigi De Giglio of Valenzano- Italy; from
K. Raghunathan of Chennai, India; from
Rob Ratkowski on Kalahaku Overlook, Haleakala National Park,
Maui;
from
Anton Balatskiy of Port Provideniya, Chukotka, Russia; from
Mariano Ribas of Buenos Aires, Argentina; from
Sylvain Weiller of Saint Rémy lès Chevreuse, France; from
Keith Breazeal of Amador County, California; from
Bryan Murahashi of San Jose, California; from
Mike Salway of Central Coast, NSW Australia;
BLUE FLASH:
On Jan. 11, Wolfgang Ott
of Stuttgart, Germany, decided to climb to the top of a television
tower to watch the sunset. Why would he do that? From up there you
can see sunsets like this:
"It was breathtaking," says Ott. "I saw my first
blue flash and managed to photograph it using my Canon
EOS 450D."
The blue flash is an elusive first cousin of the better-known green
flash. Both are caused by air temperature gradients that distort
the shape of the sun and magnify wisps of color on the sun's upper
rim. Although these mirages happen frequently, the blue flashes
they produce are seldom seen. Atmospheric optics expert Les Cowley
explains why: "The reason is that rays of the setting sun travel
through miles of our dense lower atmosphere and the air preferentially
scatters away the blue light. Dust and aerosol dim it further. But
when the air is exceptionally clean and we are above ground level
we see the blue!"
Fortunately, a TV tower is not required to experience the phenomenon.
Cowley offers these
observing tips.
Jan.
2009 Aurora Gallery
[Previous Januaries: 2008,
2007, 2005,
2004, 2001]
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