Where's Saturn? Is that a UFO--or the ISS? What's the name of that
star? Get the answers from mySKY--a
fun new astronomy helper from Meade. SOLAR
CYCLE 24: Solar physicists have been waiting
for the appearance of a reversed-polarity sunspot to signal the
start of the next solar cycle. The wait is over. A magnetically
reversed, high-latitude sunspot emerged today: image.
If you have a solar
telescope, take a look at this important new active region.
It marks the beginning of Solar Cycle 24 and the sun's slow ascent
back to Solar Maximum.
QUADRANTID METEORS:
The 2008 Quadrantid
meteor shower peaked around 0200 UTC on Friday, Jan. 4th. That
is the initial report from astronomers who flew a research airplane
north of the Arctic Circle for an uninterrupted view of the shower.
The team, led by Peter Jenniskens of the SETI Institute, witnessed
many bright Quadrantids among an "amazing display" of
aurora borealis; this is a typical view through the plane's starboard
window:
More photos from the Arctic
Quadrantid MAC flight
The timing of the peak suggests that Quadrantid debris comes from
the breakup of a comet circa 1490 AD. The largest known remaining
fragment of the comet is now catalogued as 2003
EH1, a near-Earth asteroid.
more images: from
Brian Emfinger of Ozark, Arkansas; from
Jeffrey Berkes of West Chester, PA; from
Radek Grochowski near Swidnica, Poland
TIME
BOMB: Tick-tock, tick-tock. It's been 71
days since Comet 17P/Holmes exploded on Oct.
24, 2007, brightening almost a million-fold to naked-eye visibility.
This means it could be time for another explosion. To understand
why 71 days is significant, we turn back the clock to the year 1892.
(continued below)
Above:
Comet 17P/Holmes on Jan. 3, 2008. Photo credit: Mike Holloway of
Van Buren, Arkansas: gallery.
Comet Holmes was discovered on Nov. 6, 1892, by astronomer Edwin
Holmes while he was making observations of the Andromeda Galaxy.
He noticed the comet not far from Andromeda when it "exploded"--a
brightening akin to that of Oct. 2007. It was quite a sensation
as observers around the world suddenly were able to see the comet
with the naked eye. Interest faded as the comet expanded and dimmed,
but then, 71 days later on Jan. 16, 1893, Holmes exploded again!
Deja vu?
No one knows why Holmes occasionally explodes. Theories range from
tiny moonlets crashing into the comet's icy surface to great comet-caverns
collapsing under the stress of sunlight. The interval 71 days may
have no significance at all. But on this anniversary of a double
explosion, it reminds us to keep an eye on Comet 17P/Holmes.
Finding the comet is easy. Tonight, after sunset, take your binoculars
outside and scan the northern constellation Perseus: sky
map. Holmes is readily visible as a big pale fuzzball near the
variable star Algol. On January 21-23, the comet will pass directly
in front of Algol; the view through a backyard
telescope should be dynamite!
Comet
17P/Holmes Photo Gallery
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