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SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
SPACE WEATHER
Current conditions
Solar wind
speed: 331.3 km/sec
density: 20.4 protons/cm3
explanation | more data
Updated: Today at 2246 UT
X-ray Solar Flares
6-hr max: A4
2210 UT Jan04
24-hr: B1
0310 UT Jan04
explanation | more data
Updated: Today at: 2245 UT
Daily Sun: 04 Jan 08
A new high-latitude sunspot has emerged marking the beginning of Solar Cycle 24. Credit: SOHO/MDI
Sunspot number: 13
What is the sunspot number?
Updated 03 Jan 2008
Far side of the Sun:
This holographic image seems to show a large sunspot on the far side of the sun. Confirmation is needed; check back tomorrow for updated data. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 1
quiet
explanation | more data
Current Auroral Oval:

Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES
Updated:
What is the auroral oval?
Interplanetary Mag. Field
Btotal: 4.7 nT
Bz: 3.6 nT south
explanation | more data
Updated: Today at 2247 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on Jan. 7th or 8th. Credit: SOHO Extreme UV Telescope
SPACE WEATHER
NOAA Forecasts
Updated at: 2008 Jan 04 2203 UTC
FLARE
0-24 hr
24-48 hr
CLASS M
01 %
01 %
CLASS X
01 %
01 %
Geomagnetic Storms:
Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at: 2008 Jan 04 2203 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
20 %
20 %
MINOR
10 %
10 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
25 %
25 %
MINOR
10 %
15 %
SEVERE
01 %
05 %

What's up in Space
January 4, 2008
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
[World Map of Comet Sightings]
[sky map] [ephemeris] [orbit] [comet binoculars]

Near-Earth Asteroids
Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.
On January 4, 2008 there were 916 potentially hazardous asteroids.
Jan. 2008 Earth-asteroid encounters:
Asteroid
Date(UT)
Miss Distance
Mag.
Size
2005 WJ56
Jan. 10
10.9 LD
11
1.2 km
1685 Toro
Jan. 24
76 LD
13
6.2 km
2007 TU24
Jan. 29
1.4 LD
10
400 m
Notes: LD means "Lunar Distance." 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
Essential Links
NOAA Space Weather Prediction Center
  The official U.S. government bureau for real-time monitoring of solar and geophysical events, research in solar-terrestrial physics, and forecasting solar and geophysical disturbances.
Atmospheric Optics
  The first place to look for information about sundogs, pillars, rainbows and related phenomena.
Solar and Heliospheric Observatory
  Realtime and archival images of the Sun from SOHO.
Daily Sunspot Summaries
  From the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
  more links...
©2008, SpaceWeather.com -- This site is penned daily by Dr. Tony Phillips.
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