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.
SPACESHIP SIGHTINGS:
Space shuttle Discovery is chasing the ISS
around Earth and they're a beautiful sight in the night sky. Witness
this picture taken
last night by Bryan Tobias
of San Antonio, Texas. "The ISS came first and then Discovery
12 minutes later," says Tobias. The two ships will converge
on Oct. 24th in preparation for docking on Oct. 25th. Be
alert for flybys.
HOT NEWS: Astronomers
in Japan, Persia and Europe report
that Comet 17P/Holmes is undergoing a spectacular eruption. The
17th magnitude comet has brightened by a factor of five hundred
thousand or more during the past 24 hours becoming a naked-eye object
in the evening sky. Look for a yellow 2.5th magnitude fuzzball in
the constellation Perseus after sunset. [sky
map] [ephemeris]
[3D orbit]
"This is unbelievable!" says Iranian astronomer Babak
Tafreshi. "I was amazed to find Comet Holmes so easily
with the naked-eye in the light-polluted skies of metropolitan Tehran."
Click on Tafreshi's photo to pinpoint the comet:
The outburst may signify a breakup of the comet's core or a rich
vein of ice suddenly exposed to sunlight--no one knows. At present
the comet looks more like a star than a comet; it does not have
a discernable tail, but it might grow one as the outburst continues.
Amateur astronomers are encouraged to monitor developments using
binoculars
and backyard telescopes.
Stay tuned for updates!
more images: from
P-M Hedén of Vallentuna, Sweden; from
Vladimir Ladinsky of Moscow, Russia; from
Martin McKenna of Magheram Co. Derry, N. Ireland; from
Runar Sandnes of Reed, Norway; from
Ernesto Guido and Giovanni Sostero using a remote-controlled
telescope in New Mexico.
BIG FULL MOON: This
week's full Moon is the biggest full Moon of 2007. It's no
illusion. Some full Moons are genuinely larger than others and
Thursday night's will be a whopper. Why? Read the answer below.
Left: A big, bright perigee Moon.
RIght: A lesser apogee Moon.
The Moon's orbit is an ellipse with one side 30,000 miles closer
to Earth than the other. The full Moon of Oct. 25-26 is located
on the near side, making it appear as much as 14% bigger and 30%
brighter than lesser full Moons we've seen earlier in 2007.
In the language of astronomy, the two ends of the Moon's orbit
are called "apogee"
and "perigee."
Apogee is the farthest point, perigee the nearest: diagram.
This week's full Moon is a "perigee Moon" with extra-high
"perigean
tides."
The Moon is 14% bigger, but can you actually tell the difference?
It's not so easy. There are no rulers floating in the sky to measure
lunar diameters. A fun experiment: Take a friend outside Thursday
night and ask if they notice anything unusual about the Moon. Explain
perigee after they answer.
October
2007 Aurora Gallery
[September
Gallery] [Aurora Alerts]
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