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CALIFORNIA LANDING:
Bad weather over Florida has forced NASA
to target Edwards Air Force Base in California for today's landing
of space shuttle Discovery. The deorbit burn is scheduled to begin
at 7:47 p.m. EDT for an 8:53 p.m. landing at Edwards. [ground
tracks] [updates]
SPACE STATION FLARES:
One of the pleasures of watching the International
Space Station (ISS) glide across the night sky is the unexpected.
You never know when the ISS is going to flare. "Last night,
I caught a beautiful flash of light coming from the space station,"
reports Tamas Ladanyi of Bend, Hungary. The flare occured just as
the ISS was passing behind the battlement of a local castle:
"The parallel streak of light is space shuttle
Discovery, which undocked from the ISS on Sept. 8th," says
Ladanyi. Discovery did not flare, however, because the aerodynamic
shuttle is too curvaceous.
Space station flares happen when sunlight glints off
something flat--e.g., a solar array, a thermal radiator, an airlock
door. The ISS has thousands of square feet of planar surfaces oriented
at a variety of sun-angles. It's such a complicated
situation, no one can predict when a glint will occur or where
the reflected rays will fall on Earth.
On Sept. 10th, it was a castle in Hungary. Your back
yard could be next. Check the Simple Satellite
Tracker for a shot at the unexpected.
more images: from
Tom King of Watauga, Texas; from
Monika Landy-Gyebnar of Bánd, Hungary; from
Jared Aicher of Boise, Idaho; from
Blattmann of Saint-Etienne de Crossey, France; from
Martin Wagner of Sonnenbuehl-Genkingen, Germany
STAR TRAILS IN MOTION:
It's an astrophotographer's favorite trick:
Point your camera at the stars, open the shutter, and let the world
turn. The rotation of the planet beneath your feet causes the stars
overhead to curve in graceful arcs known as star trails. Here
are
some
examples.
Renowned astrophotographer Miguel Claro has added a new wrinkle
to the old favorite. Click on the image to see star trails in
motion:
"I made the movie on September 1st with my camera (Canon
400D) set up in a farm field in Vila Boim, Portugal, about 200km
from Lisbon," says Claro. "It consists of sixty-eight
30-second exposures. Later I combined the individual images using
Windows Movie Maker."
Each frame in the movie is the sum of all the previous frames.
Because of this, "as we advance in the film, the signal-to-noise
ratio increases. It's an interesting visual sensation." Watch
for it as you play
the movie again.
Star trails in motion: It's the astrophotographer's new favorite
trick.
August
2009 Aurora Gallery
[previous Augusts: 2008,
2007, 2006,
2005, 2004,
2003, 2002,
2001]
Explore
the Sunspot Cycle
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