SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 440.5 km/s
density: 3.5 protons/cm³
explanation | more data
Updated: Today at 1046 UT

X-ray Solar Flares
6-hr max: A9 0755 UT Feb17
24-hr: A9 0755 UT Feb17
explanation | more data
Updated: Today at 1045 UT

Daily Sun: 17 Feb '06

Micro-sunspot 854 poses no threat for solar flares. Credit: SOHO/MDI

Sunspot Number: 27
What is the sunspot number?
Updated: 16 Feb 2006

Far Side of the Sun

This holographic image reveals no large sunspots on the far side of the sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
B_total: 4.3 nT
B_z: 1.4 nT south
explanation | more data
Updated: Today at 1047 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole should reach Earth on or about Feb. 20th. . Image credit: SOHO Extreme UV Telescope.

SPACE WEATHER
NOAA
Forecasts
Solar Flares: Probabilities for a medium-sized (M-class) or a major (X-class) solar flare during the next 24/48 hours are tabulated below.
Updated at 2006 Feb 16 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 2006 Feb 16 2203 UTC
Mid-latitudes

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

High latitudes

	0-24 hr	24-48 hr
ACTIVE	20 %	20 %
MINOR	05 %	05 %
SEVERE	01 %	01 %

What's Up in Space -- 17 Feb 2006
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ALIEN LIGHTNING: NASA's Cassini spacecraft is tracking an intense lightning storm on Saturn. The powerful bolts are causing the spacecraft's radio instruments to "crackle"--much like the crackles you hear coming from your car's AM radio when you drive by a thunderstorm on Earth. One difference: Saturn's lightning is about 1000 times stronger than Earth's: full story.

Listen to Saturn's Lightning

SOLAR PROMINENCE: "I'm celebrating Galileo's birthday for 2 days in the row," says photographer Mila Zinkova of San Francisco, California. "Yesterday there was a huge shark's fin prominence and today there is a huge erupting prominence." She snapped this picture on Feb. 16th:

Earth added for comparison

If you have a safely-filtered solar telescope, keep an eye on the the limb of the sun. It's a busy place.

more images: from Andy Dodson of Huirangi, New Zealand; from John Stetson of Falmouth, Maine; from Peter Paice of Belfast, Northern Ireland;

HAPPY BIRTHDAY, GALILEO: On February 15, 1564, Galileo Galilei was born in Pisa, Italy. If he were alive today he would be 442 years old. Galileo is an important person in the history of space weather. Contrary to popular belief, he didn't discover sunspots, but he was one of the first to observe them using a telescope.

In Galileo's day, many people believed sunspots were satellites of the sun. Galileo proved otherwise. By drawing sunspots every day, he discovered that the sun spins and that sunspots are located on (or very near) the sun's surface. Galileo thought sunspots might be clouds.

Sunspots drawn by Galileo in June 1612: more.

Now we know what sunspots really are: great islands of magnetism. Sunspots consist of magnetic force fields poking through the surface of the sun. These fields block the flow of heat from below. Because sunspots are a few thousand degrees cooler than the surrounding inferno, they appear dark. Typical sunspots are a few times wider than Earth. The behemoths Galileo sketched in 1612 were as wide as Jupiter.

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 17 Feb 2006 there were 772 known Potentially
Hazardous Asteroids January 2006 Earth-asteroid encounters

ASTEROID	DATE (UT)	MISS DISTANCE	MAG.	SIZE (meters)
2005 XO4	Jan. 1	18.5 LD	20+	~150 m
2005 YM128	Jan. 1	19.8 LD	19	~75 m
2005 YO128	Jan. 3	6.5 LD	16	~60 m
2006 AB3	Jan. 4	13.5 LD	21	~15 m
2005 YU8	Jan. 13	19.8 LD	19	~70 m
2006 AN	Jan. 13	18.5 LD	20	~50 m

Notes: LD is a "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 Web Links

NOAA Space Environment 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. See also Snow Crystals.

Solar and Heliospheric Observatory -- Realtime and archival images of the Sun from SOHO. (European Mirror Site)

Daily Sunspot Summaries -- from the NOAA Space Environment Center.

Current Solar Images --a gallery of up-to-date solar pictures from the National Solar Data Analysis Center at the Goddard Space Flight Center. See also the GOES-12 Solar X-ray Imager.

Recent Solar Events -- a nice summary of current solar conditions from lmsal.com.

SOHO Farside Images of the Sun from SWAN and MDI.

The Latest SOHO Coronagraph Images -- from the Naval Research Lab

Daily images from the sun -- from the Big Bear Solar Observatory

List of Potentially Hazardous Asteroids -- from the Harvard Minor Planet Center.

Observable Comets -- from the Harvard Minor Planet Center.

What is the Interplanetary Magnetic Field? -- A lucid answer from the University of Michigan. See also the Anatomy of Earth's Magnetosphere.

Real-time Solar Wind Data -- from NASA's ACE spacecraft. How powerful are solar wind gusts? Read this story from Science@NASA.

More Real-time Solar Wind Data -- from the Solar and Heliospheric Observatory Proton Monitor.

Lists of Coronal Mass Ejections -- from 1998 to 2001

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006;

Space Audio Streams: (University of Florida) 20 MHz radio emissions from Jupiter: #1, #2, #3, #4; (NASA/Marshall) INSPIRE: #1; (Stan Nelson of Roswell, New Mexico) meteor radar: #1, #2;

Recent International Astronomical Union Circulars

GLOSSARY | SPACE WEATHER TUTORIAL