| FLYBY ALERT!
Space shuttle Discovery launches on May 31st. Get your flyby
alerts from Space
Weather PHONE |
|
|
TWIST AND SHOOT:
Last week, over a period of two days (May 9th and 10th), NASA's
Stereo-B spacecraft observed a troupe of magnetic filaments dancing
along on the limb of the sun. For reasons that will become clear
when you watch the performance, mission scientists have entitled
the movie Twist and Shoot: 4.4
MB Quicktime, 8.1
MB mpeg.
ISS MARATHON:
The 2008 "ISS Marathon" gets underway this week when the
International Space Station spends three days (May 21-23) in almost-constant
sunlight. Sky watchers in Europe and North America can see the bright
spaceship gliding overhead two to four times each night. Please
try our new and improved Simple Satellite Tracker
to find out when to look.
The station is not only bright and easy to see with the naked eye,
but also it makes a fine target for backyard telescopes:
Click
to the view the 0.9 MB movie
"I took these pictures during the early morning hours of May
12th using a 5-inch refracting telescope." says amateur astronomer
Dirk Ewers of Hofgeismar,
Germany. For five minutes, he tracked the ISS across the sky and
his movie of the entire 75o transit is a must
see.
3D BONUS: Grab your
3D
glasses. Spaceweather reader Sylvain Weiller of France has combined
two frames of Dirk Ewer's movie to create a stereo
view of the space station. If you don't have 3D glasses, try
the cross-eyed
version instead.
HALE'S LAW:
On the sun this weekend, "four new active regions have appeared
for us to look at in awe and wonderment," reports Stephen Ames
of Hodgenville, Kentucky, who sends this
sketch of the view through his Coronado
PST. Each "active region" is a small sunspot or proto-sunspot
struggling to coelesce.
Because these regions straddle the sun's equator, they nicely illustrate
a basic law of sunspots: Hale's Law states that sunspots on opposite
sides of the sun's equator have opposite magnetic polarity. Consider
this magnetic map made by the Solar and Heliospheric Observatory
(SOHO) on May 17th:
White represents N magnetic polarity; black represents
S.
Sunspots are essentially magnetic, and each spot has its own "personal"
north and south magnetic pole. Above the sun's equator, the poles
are arranged S-N; below the sun's equator, they are reversed, N-S.
That's Hale's Law, named after George
Ellery Hale, who studied the magnetism of sunspots in the early
20th century.
more images: from
Matthias Juergens of Gnevsdorf, Germany; from
Pavol Rapavy of Rimavska Sobota, Slovakia; from
Michael Borman of Evansville, Indiana; from
Peter Paice of Belfast, Northern Ireland;
April
2008 Aurora Gallery
[Aurora Alerts] [Night-sky
Cameras] |
