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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Current conditions
Solar wind
speed: 373.9 km/sec
density: 7.9 protons/cm3
explanation | more data
Updated: Today at 2343 UT
X-ray Solar Flares
6-hr max: A9
2325 UT Dec25
24-hr: B1
0330 UT Dec25
explanation | more data
Updated: Today at: 2340 UT
Daily Sun: 25 Dec. 09
The Earth-facing side of the sun is blank--no sunspots. Image credit: SOHO/MDI
Sunspot number: 11
What is the sunspot number?
Updated 24 Dec 2009

Spotless Days
Current Stretch: 0 days
2009 total: 259 days (72%)
Since 2004: 770 days
Typical Solar Min: 485 days
explanation | more info
Updated 24 Dec 2009

The Radio Sun
10.7 cm flux: 77 sfu
explanation | more data
Updated 24 Dec 2009

Far side of the Sun:
This holographic image reveals no sunspots on the far side of the sun. Image credit: SOHO/MDI
Planetary K-index
Now: Kp= 2 quiet
24-hr max: Kp= 2
explanation | more data
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Interplanetary Mag. Field
Btotal: 5.1 nT
Bz: 2.1 nT north
explanation | more data
Updated: Today at 2345 UT
Coronal Holes:
There are no large coronal holes in the Earth-facing side of the sun. Credit: SOHO Extreme UV Telescope
NOAA Forecasts
Updated at: 2009 Dec 25 2201 UTC
0-24 hr
24-48 hr
01 %
01 %
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: 2009 Dec 25 2201 UTC
0-24 hr
24-48 hr
10 %
05 %
01 %
01 %
01 %
01 %
High latitudes
0-24 hr
24-48 hr
15 %
05 %
01 %
01 %
01 %
01 %
What's up in Space
December 25, 2009

ASTRONOMY ALERTS: Looking for a unique and affordable gift? Give the heavens for Christmas at Spaceweather PHONE.


BIG INTERSTELLAR DISCOVERY: The solar system is passing through an interstellar cloud that physics says should not exist. In the Dec. 24th issue of Nature, a team of scientists reveal how NASA's Voyager spacecraft have solved the mystery. Get the full story from Science@NASA.

AURORAS AND A RAINBOW AT NIGHT: At midnight on Dec. 23rd, Karl Johnston found himself climbing down a cliff on the banks of the Slave River, near Fort Smith in the Northwest Territories of Canada. He paused for breath, looked out over the rapids, and this is what he saw:

"A rainbow was cutting through the aurora borealis," he says.

A rainbow at night? "Moonlight was shining into the mist above the rapids--and that's what made the rainbow," he explains. Technically, it's called a fogbow. Fogbows are close cousins of rainbows and they are formed in essentially the same way: light bounces in and out of water droplets to produce a luminous arc.

Johnston's lunar fogbow formed above the rapids just as a solar wind stream was buffeting Earth's magnetic field, giving rise to auroras and a rare conjunction of Arctic night lights. It's enough to make you scale a cliff at midnight. More images: #1, #2, #3.

UPDATED: December Northern Lights Gallery
[previous Decembers: 2008, 2007, 2006, 2005, 2001, 2000]

RINGED PLANET: Saturn isn't the only planet with rings. Earth has one, too, a ring of geostationary satellites. Click on this image and cross your eyes to see it pop out of the screen in 3D:

Science teacher Tom Wagner of Waterloo, Iowa, created the image on Christmas Eve using Makoto Kamada's 3D satellite viewing program. "Earth looks a bit like a Christmas ornament hanging suspended in the middle of the satellite swarm."

Geostationary satellites orbit 36,000 kilometers above Earth's surface. They go around our planet once every 24 hours, which means they hang over a fixed point on the ground--perfect for monitoring weather, beaming down TV signals, and relaying telecommunications. The ring is sometimes called the "Clarke Belt" after Arthur C Clarke who popularized the idea of geostationary satellites in the mid-1940s, more than a decade before the Space Age began.

In addition to the Clarke Belt, Wagner's image also shows hundreds of low-Earth orbit satellites hugging the planet only a few hundred kilometers high, and many satellites at intermediate altitude. Space is a busy place. You can see how busy by viewing more of Wagner's 3D-sat images here.

Explore the Sunspot Cycle

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 December 25, 2009 there were 1091 potentially hazardous asteroids.
Dec. 2009 Earth-asteroid encounters:
Miss Distance
2009 WV25
Dec. 1
2.9 LD
65 m
2009 WA52
Dec. 5
8.2 LD
23 m
2002 WP
Dec. 6
71.2 LD
950 m
2009 XO2
Dec. 23
8.6 LD
85 m
2009 YR
Dec. 25
4.3 LD
10 m
24761 Ahau
Jan. 11
70.8 LD
1.4 km
2000 YH66
Jan. 12
69.5 LD
1.1 km
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 space weather bureau
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.
  3D views of the sun from NASA's Solar and Terrestrial Relations Observatory
Daily Sunspot Summaries
  from the NOAA Space Environment Center
Current Solar Images
  from the National Solar Data Analysis Center
Science Central
  more links...
©2008, -- This site is penned daily by Dr. Tony Phillips.













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