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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: 305.1 km/s
density:
3.2 protons/cm3
explanation | more data
Updated: Today at 2246 UT

X-ray Solar Flares
6-hr max:
B1 1805 UT May17
24-hr: B5 1255 UT May17
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 17 May '07

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


Sunspot Number: 56
What is the sunspot number?
Updated: 16 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: 7.3 nT
Bz:
5 nT south
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 17 2203 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 25 % 25 %
CLASS X 05 % 05 %

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 17 2203 UTC
Mid-latitudes
0-24 hr 24-48 hr
ACTIVE 15 % 25 %
MINOR 01 % 10 %
SEVERE 01 % 05 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 15 % 25 %
MINOR 05 % 15 %
SEVERE 01 % 05 %

What's Up in Space -- 17 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.

SUNSET PLANETS: When the sun goes down tonight, step outside and look west into the glow of sunset. You may be able to see Mercury and a super-slender crescent Moon hanging together just above the horizon. It's a beautiful sight, improved by the use of binoculars. Take a look! [sky map]

images: from Michael Bromley at the Kufrah Oasis in the Sahara Desert of Libya

RADIO-ACTIVE SUNSPOT: "After a long quiet spell, the sun is making noise again," reports Thomas Ashcraft of New Mexico. On Maqy 15th, using a 21 MHz ham rig, he recorded the roaring sounds of a Type III solar radio burst: listen.

A broadband radio telescope at the University of Florida Radio Observatory detected the same burst. The plot, below, shows how energy was spread across the shortwave spectrum:

David Thomas of Lynchburg, Virginia, recorded yet another outburst on May 15th using his RadioJove amateur radio telescope: data.

The source of all this activity is young sunspot 956. The sunspot emerged near the sun's eastern limb less than 48 hours ago and has been growing at breakneck speed every since. In addition to the radio bursts, the sunspot also produced a beautiful coronal mass ejection: movie.

Ham radio operators may wish to point their Yagis toward the sun. Sunspot 956 is crackling with small solar flares and may produce more radio bursting in the days ahead. Stay tuned!

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 17 May 2007 there were 861 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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