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

SpaceWeather.com
Science news and information about the Sun-Earth environment.

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 573.2 km/s
density:
2.0 protons/cm3
explanation | more data
Updated: Today at 2245 UT

X-ray Solar Flares
6-hr max:
A6 1915 UT May18
24-hr: A7 0250 UT May18
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 18 May '07

Sunspot 956 has developed a delta-class magnetic field that harbors energy for X-class solar flares. Credit: SOHO/MDI


Sunspot Number: 30
What is the sunspot number?
Updated: 17 May 2007

Far Side of the Sun

This holographic image reveals an old friend, photogenic sunspot 953 on the farside of the sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
Btotal: 8.0 nT
Bz:
3.7 nT north
explanation | more data
Updated: Today at 2246 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole will reach Earth on May 19th or 20th. 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 May 18 2203 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 15 % 15 %
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 May 18 2203 UTC
Mid-latitudes
0-24 hr 24-48 hr
ACTIVE 25 % 20 %
MINOR 10 % 05 %
SEVERE 05 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 45 % 25 %
MINOR 25 % 15 %
SEVERE 15 % 05 %

What's Up in Space -- 18 May 2007
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What's the name of that star? Where's Saturn? Get the answers from mySKY--a fun new astronomy helper from Meade.

SUNSPOT 956: Sunspot 956 continues to grow (movie) and it now has a complex magnetic field that habors energy for X-class solar flares. NOAA forecasters estimate a 5% chance of such an explosion during the next 24 hours. Stay tuned.

SUNSET PLANETS: Photographer Martin Gembec of the Czech Republic calls this a "good sky." The glow of sunset, the planet Mercury, and a whisper-thin crescent Moon:


Photo details: Canon 300D, Sigma 135mm lens, ISO 400, 0.5 sec exp.

He took the picture last night while the Moon was passing by Mercury. Consider it a preview: On Saturday night, May 19th, the crescent Moon will pass even closer to Venus, and it is a sight you must not miss. Venus and the crescent Moon will lie barely 1o apart, forming a brilliant and unforgettable pair. When the sun goes down on Saturday, be outside looking west: sky map.

more images: from Stephane Levesque of Ste Luce, Quebec; from Jan Koeman of Kloetinge, the Netherlands; from Chuck Hunt of Brook Park, Ohio; from Michael Bromley at the Kufrah Oasis in the Sahara Desert of Libya; from Anirudh Walvekar of Cuyahoga Falls, Ohio; from Helmut Groell of Moers, Germany; from Günther Strauch of Borken, Germany; from Pete Lawrence of Selsey, UK.

GALACTIC FOSSIL: "The scientific community is still buzzing about the discovery of HE 1523-0901, a 13.2 billion year old star which formed a mere 500 million years after the Big Bang," says Anthony Ayiomamitis of Athens, Greece. "I took this picture of the star on May 13th."


Photo details: 160mm Starfire telescope, SBIG ST-2000XM, 2 hr exposure.

Indicated by the arrow, HE 1523-0901 is 11th magnitude and located in the constellation Libra. It looks much like any other star in the area--but it is special. HE 1523-0901 is one of the oldest stars in the Milky Way, perhaps one of the oldest in the Universe, and by studying it astronomers may be able to learn new things about the genesis of our galaxy.

A team of astronomers led by Anna Frebel of the University of Texas dated the star using a technique similar to carbon-14 dating. HE 1523-0901 contains radioactive elements uranium and thorium. (These elements leave their imprint on the star's spectrum, which is how they can be detected and measured.) By comparing the abundance of uranium and thorium to other elements in the star which do not decay, the researchers were able to make six independent estimates of the star's age, and they all agreed: 13.2 billion years. Click here to read the original research.



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 18 May 2007 there were 863 known Potentially
Hazardous Asteroids

May 2007 Earth-asteroid encounters
ASTEROID

 DATE
(UT)

MISS DISTANCE

MAG.

 SIZE
1862 Apollo

May 8

72 LD

13

2.4 km
2007 JD

May 11

12 LD

18

100 m
2007 JZ2

May 14

7.0 LD

19

30 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.

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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