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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: 411.1 km/sec
density: 7.4 protons/cm3
explanation | more data
Updated: Today at 2145 UT
X-ray Solar Flares
6-hr max: A0
2145 UT Jan28
24-hr: A0
2145 UT Jan28
explanation | more data
Updated: Today at: 2145 UT
Daily Sun: 28 Jan 08
The sun is blank--no sunspots. Credit: SOHO/MDI
Sunspot number: 0
What is the sunspot number?
Updated 28 Jan 2008
Far side of the Sun:
This holographic image reveals no large sunspots on the far side of the sun. 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: 4.0 nT
Bz: 2.2 nT north
explanation | more data
Updated: Today at 2147 UT
Coronal Holes:
A solar wind stream flowing from the indicated coronal hole should reach Earth on or about Jan. 31st. Credit: Hinode X-Ray Telescope.
SPACE WEATHER
NOAA Forecasts
Updated at: 2008 Jan 27 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 27 2203 UTC
Mid-latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
10 %
MINOR
05 %
05 %
SEVERE
01 %
01 %
High latitudes
0-24 hr
24-48 hr
ACTIVE
10 %
15 %
MINOR
05 %
05 %
SEVERE
01 %
01 %

What's up in Space
January 28, 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.

ASTEROID FLYBY: Asteroid 2007 TU24 is approaching Earth and NASA radars have measured its size and shape: 250 meters wide and lopsided. There's no danger of a collision, but on Jan. 29th the space rock will be close enough (1.4 lunar distances) to photograph through backyard telescopes as it speeds through the constellation Cassiopeia glowing like a 10th magnitude star. [ephemeris] [3D orbit] [radar image]

KERN ARC: To the casual observer, this photo of ice halos around the sun taken by Marko Mikkilä of Finland may not seem extraordinary, but to experts it is "the halo photo of the decade." The excitement springs from a faint circle around the zenith labeled "Kern arc":

The rare Kern arc completes the circle of the much brighter and frequently seen circumzenithal arc. "Kern arc sightings are few indeed, only two or three reports in the last century, and it has never ever been photographed--until Mikkilä did it last Nov. 17th," says atmospheric optics expert Les Cowley.

"As a diamond dust swarm generated the halo, Mikkilä took dozens of images. The picture above is a stack of 16 images. Astronomers use stacking to reveal faint or elusive details and it does the same for halo displays. However, Mikkilä’s Kern arc was so clear that it is visible on individual images."

"Why is the Kern arc so very rare? The arc has a ray path like that of the circumzenithal arc but with a crucial extra reflection inside flat plate crystals. The contorted path is not possible inside ordinary regular hexagonal plates, instead they have to be almost triangular. Mikkilä sampled and photographed under a microscope the crystals falling around him and lo, many had the required triangular shape."

"The next time you see a bright grin in the sky, look around for the complete circle," urges Cowley. "You might catch a Kern arc of your own."

NEW: Spaceweather.com has a new tool for reader discussion. Click on this symbol to add your comments to a story.

LIGHT POLLUTION FROM 24,000 FT: On Jan. 15th, Rick Stankiewicz looked out the window from his seat aboard a night flight from Toronto to Thunder Bay, Ontario. "I expected to see a blank slate of clouds," he says. "Instead I noticed orange glowing patches."

"It was all too obvious what I was observing," continues Stankiewicz. "These glowing cloud patches were indicators of light pollution from communities across southwestern Ontario. This misdirected and wasted light was filtering through the cloud deck to my airplane window at 24,000 ft. I was amazed at their number; within minutes, I counted dozens of glowing patches. I used my digital camera (a Canon 400D) to capture as best as I could what I saw. There is no denying it; societies beacons of light are also signposts of wasted energy and resources."

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. [comment]
On January 28, 2008 there were 921 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
2008 AF3
Jan. 13
1.0 LD
14
27 m
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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