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A SUNSPOT IN THE
OFFING? Astronomers are watching the edge
of the sun, waiting for the emergence of an active region that produced
a bright CME on May 5th: movie.
At the time of the explosion, the blast site was hidden behind the
sun's eastern limb, but now solar rotation is turning the region
toward Earth for a better view. Will a sunspot appear to break the
monotony of the blank
sun? Stay tuned.
ISS COMPANION:
This morning, May 7th, the International Space Station flew directly
over the Netherlands. Astronomer Ralf Vandebergh was watching and
noticed, about 90 seconds later, another spacecraft following the
ISS. He photographed the pair using his backyard 10-inch telescope:
"The second spacecraft was the Progress 32 rocket, which undocked
from the ISS yesterday," he says. The Russian rocket delivered
a load of supplies to the ISS in February and now it is taking away
a load of trash. The Progress and its contents are scheduled to
re-enter Earth's atmosphere and disintegrate over the Pacific Ocean
on May 18th. Meanwhile, the rocket can be seen tagging along behind
the ISS; check the Simple Satellite Tracker
for flyby times.
NAME THAT PLANET:
Glance at the photo. The technicolor streak is one of the planets
in our Solar System. Can you guess which one? Scroll down for the
answer.
It's Mercury. Photographer Darren Baskill of East
Sussex, UK, explains: "Mercury was low on the horizon and its
light had to travel through a large amount of air." Refraction
by thermal irregularities in the atmosphere caused Mercury to scintillate
(twinkle) with all the colors of the rainbow. "So, at one moment
Mercury appeared red, at others green, and at other moments, blue.
I took a half-second-long photograph of Mercury, moving the camera
around during that half-second, so that the changing colours of
Mercury could be caught on camera. This image is a combination of
three such exposures simply overlayed on top of each other."
This phenomenon is even easier to see in the Dog Star,
Sirius, which is more luminous than Mercury and also near the horizon
after sunset. Point your optics southwest as the twilight fades
to black: sky map.
April
2009 Aurora Gallery
[previous Aprils: 2008,
2007, 2006,
2005, 2004,
2003, 2002]
Explore
the Sunspot Cycle
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