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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: 328.2 km/sec
density: 1.5 protons/cm³
explanation | more data
Updated: Today at 2345 UT

X-ray Solar Flares
6-hr max: B2 2325 UT Dec20
24-hr: B2 2325 UT Dec20
explanation | more data
Updated: Today at: 2340 UT

Daily Sun: 20 Dec. 09

All three of these sunspots are members of new Solar Cycle 24. The image is purple because was taken through a violet Calcium-K filter sensitive to the light emitted by magnetic froth around sunspots. Image credit: Stefano Sello of Pisa, Italy

Sunspot number: 43
What is the sunspot number?
Updated 19 Dec 2009

Spotless Days
Current Stretch: 0 days
2009 total: 259 days (73%)
Since 2004: 770 days
Typical Solar Min: 485 days
explanation | more info
Updated 19 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= 0 quiet
24-hr max: Kp= 1 quiet
explanation | more data

Current Auroral Oval:

Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/POES

Interplanetary Mag. Field
B_total: 1.6 nT
B_z: 0.5 nT south
explanation | more data
Updated: Today at 2346 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole could reach Earth on or about Dec. 22nd. Credit: SOHO Extreme UV Telescope

SPACE WEATHER
NOAA Forecasts

Updated at: 2009 Dec 20 2201 UTC

FLARE	0-24 hr	24-48 hr
CLASS M	10 %	05 %
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: 2009 Dec 20 2201 UTC

Mid-latitudes

	0-24 hr	24-48 hr
ACTIVE	10 %	05 %
MINOR	01 %	01 %
SEVERE	01 %	01 %

High latitudes

	0-24 hr	24-48 hr
ACTIVE	15 %	05 %
MINOR	01 %	01 %
SEVERE	01 %	01 %

What's up in Space

December 20, 2009

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

DECEMBER SOLSTICE: The December solstice occurs on Monday, Dec. 21st, at 1747 UT (12:47 pm EST) when the sun dips to its lowest celestial latitude of the year. The event marks the beginning of summer in the southern hemisphere and winter in the northern hemisphere--and some wonderful sunsets at Stonehenge. Happy Solstice!

SUNSET SKY SHOW: When the sun sets tonight, go outside and look up. Jupiter and the crescent Moon will be shining side-by-side in the southwestern sky. P-M Hedén sends this photo of his children enjoying the view from Vallentuna, Sweden:

Advice: Look before the sky fades all the way to black. A bright conjunction of worlds framed by twilight blue is an especially lovely sight. [sky map]

more images: from Rafael Schmall of Hungary, Somogy, Kaposfo; from Mark Claudel Arzadon of San Jacinto, Pangasinan, Philippines; from Geir Øye of Ørsta, Norway; from Tamás Ábrahám of Zsámbék, Hungary; from Stefano De Rosa of Turin, Italy;

SOLAR TRANSIT: Yesterday, amateur astronomer Lars Zielke was photographing sunspot 1035 using a solar telescope at his backyard observatory in Tvis, Denmark. Everything was going fine when suddenly a shadowy black form transited the field of view:

"Normally these kinds of black spots are caused by birds or bugs," he says. "But today I found something very interesting. Please see the movie where I have slowed down the speed to 4 frames per second from the original 60 fps."

Mystery solved. Merry Christmas!

more sunspot photos: from Rogerio Marcon of Campinas - Brasil; from John C McConnell of Maghaberry, Northern Ireland; from Pete Lawrence of Selsey, West Sussex, UK; from Jimmy Eubanks of Boiling Springs, SC; from Steve Riegel of Santa Maria, CA; from Cai-Uso Wohler of Bispingen, Germany; from Peter Paice of Belfast, Northern Ireland;

2009 Geminid Meteor Gallery
[sky map] [meteor radar] [Geminid counts]

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

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 20, 2009 there were 1090 potentially hazardous asteroids.

Dec. 2009 Earth-asteroid encounters:

Asteroid	Date(UT)	Miss Distance	Mag.	Size
2009 WV25	Dec. 1	2.9 LD	16	65 m
2009 WA52	Dec. 5	8.2 LD	20	23 m
2002 WP	Dec. 6	71.2 LD	16	950 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 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.

STEREO

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