Set your alarm for dawn. On Thursday morning,
May 21st, Venus, Mars and the crescent Moon will form a lovely triangle
in the eastern sky. It's a nice way to begin the day. Sky
20, May 21.
SPACESHIPS IN THE
SUN, AGAIN: How often do you see spaceships
flying in front of the sun? Astrophotographer Thierry
Legault has seen it happen three times in the past week. Here
he is standing on the grounds of the Kennedy Space Center with his
solar-filtered telescope trained on the action:
The view through the eyepiece looked like
this. It shows space shuttle Atlantis with the Hubble Space
Telescope in the cargo bay on May 18th during the fifth and final
spacewalk of the STS-125 Hubble repair mission.
"One hour after I took the picture, rain began to fall and
it hasn't stopped for 30 hours," says Legault. "Note the
shuttle sitting on pad 39B over my left shoulder. That is Endeavour,
ready to fly to the rescue in the unlikely case that Atlantis could
not come back."
Legault also photographed a solar transit of Atlantis on
May 12th and a transit of Hubble and Atlantis in tandem on
May 13th. That makes three times. You never know what you might
see when you look
at the sun.
from the sun are brief and elusive. You can miss one simply by blinking.
So imagine the surprise of Lance
B. of the Cayman islands on May 17th when he watched a flash
endure for two ... long ... seconds. "I had enough time to
take this picture," he says:
The green spot on the horizon is the flash showing
itself during the very last seconds of sunset.
Green flashes happen when the normally mild
refraction of Earth's atmosphere is amplified
by a mirage. "The mirage occurs when there is warm air immediately
over the ocean and the air temperature gradient changes rapidly
with height," says atmospheric optics expert Les Cowley. "For
the flash to be visible the warm air layers must be below you."
"The air was still and very hot; I knew the conditions
were favorable," says Lance. "This was the longest green
flash I've ever seen!"
more images: from
Paul Edmondson of Point Reyes, CA; from
Wolfgang Ott of Stuttgart, Germany; from
James Helmericks of Colville River Delta, Northern Alaska;
2009 Aurora Gallery
[previous Aprils: 2008,
the Sunspot Cycle