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

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Science news and information about the Sun-Earth environment.

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 612.7 km/s
density:
1.3 protons/cm3
explanation | more data
Updated: Today at 2241 UT

X-ray Solar Flares
6-hr max:
A5 1845 UT Feb15
24-hr: A9 1500 UT Feb15
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 15 Feb '07

The sun is blank today and solar activity is very low. Credit: SOHO/MDI!


Sunspot Number: 0
What is the sunspot number?
Updated: 14 Feb 2007

Far Side of the Sun

This holographic image reveals one or two sunspot group on the far side of the sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
Btotal: 4.2 nT
Bz:
3.0 nT north
explanation | more data
Updated: Today at 2243 UT

Coronal Holes:

Earth is inside a solar wind stream flowing from the indicated coronal hole. 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 2007 Feb 15 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 2007 Feb 15 2203 UTC
Mid-latitudes
0-24 hr 24-48 hr
ACTIVE 20 % 15 %
MINOR 10 % 05 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 30 % 25 %
MINOR 15 % 15 %
SEVERE 05 % 05 %

What's Up in Space -- 15 Feb 2007
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Cards, flowers, chocolate... what's missing? The heavens. Spaceweather PHONE for Valentine's Day.

HAPPY BIRTHDAY, GALILEO: On February 15, 1564, Galileo Galilei was born in Pisa, Italy. If he were alive today, he would be 443 years old. Galileo is an important figure in the history of space weather. How so? Keep reading.

AURORA BOREALIS: In 1619, Galileo coined the term "aurora borealis." He thought auroras were sunlight reflected from the atmosphere, and so he named the phenomenon after Aurora, the Roman goddess of morning.

Four centuries later we know better, but Galileo's nomenclature is still used. Just yesterday, sky watchers from Scandinavia to Alaska witnessed a beautiful display of "auroras" when a solar wind stream hit Earth's magnetic field:


Photo details: Canon EOS 5D, 24 mm:1.4 lens, 4 seconds exposure.

"Great show!," says Swedish photographer Peter Rosen. "The temperature here in Abisko was minus 25 degrees, but Aurora kept me warm."

February Aurora Gallery
[aurora alerts] [night-sky cameras]

BONUS: "I live in Pisa, Italy," says photographer Riccardo Di Nasso, "and the house where Galileo was born is still standing." He photographed himself in front of Galileo's "Casa Ammannati" earlier today: image.

SUNSPOTS: Contrary to popular belief, Galileo did not 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 must be located on or close to the sun's surface. Personally, Galileo thought sunspots were clouds.


Above: 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 sun's surface. These fields block the flow of heat from below, cooling the sun in their vicinity. Because sunspots are so cool, "only" a few thousand degrees, they appear dark compared to the surrounding inferno.

If Galileo were with us today, he wouldn't be impressed. The sun is utterly blank. 2007 is a year of solar minimum, and sunspots are somewhat rare. A better birthday would be the year 2010 when Solar Max comes roaring back. Stay tuned--and many happy returns.

BONUS: To celebrate Galileo's birthday, John Stetson of Falmouth, Maine, created this beautiful composite of spiral sunspot 940, which he photographed crossing the sun recently. Galileo never saw anything like that!



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 15 Feb 2007 there were 843 known Potentially
Hazardous Asteroids

Feb-Mar 2007 Earth-asteroid encounters
ASTEROID

 DATE
(UT)

MISS DISTANCE

MAG.

 SIZE
2006 AM4

Feb. 1

5.2 LD

16

180 m
2007 BZ48

Feb. 7

4.5 LD

18

30 m
2006 VV2

Mar. 31

8.8 LD

9

2 km
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.

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 -- from the National Solar Data Analysis Center

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

What is the Magnetosphere?

The Lion Roars -- visit this site to find out what the magnetosphere sounds like.

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

Observable Comets -- from the Harvard Minor Planet Center.

Real-time Solar Wind Data -- from NASA's ACE spacecraft.

How powerful are solar wind gusts? Not very! 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 1996 to 2006

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1994, 1995, 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006; Apr-Jun 2006; Jul-Sep 2006; Oct-Dec 2006.

This site is penned daily by Dr. Tony Phillips: email


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