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<<back forward>> -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids
Science news and information about the Sun-Earth environment.


Solar Wind
speed: 347.4 km/s
2.8 protons/cm3
explanation | more data
Updated: Today at 2256 UT

X-ray Solar Flares

6-hr max:
X5 2105 UT Sep08
24-hr: X5 2105 UT Sep08
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 07 Sep '05

Tiny sunspot 805 poses no threat for strong solar flares, but newly-emerging sunspot on the east limb could unleash powerful X-flares. Credit: SOHO/MDI

Sunspot Number: 11
What is the sunspot number?
Updated: 07 Sep 2005

Far Side of the Sun

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

Interplanetary Mag. Field
Btotal: 6.6 nT
1.1 nT north
explanation | more data
Updated: Today at 2256 UT

Coronal Holes:

There are no large coronal holes on the Earth-facing side of the sun.Image credit: NOAA Solar X-ray Imager.


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 2005 Sep 07 2204 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 70 % 75 %
CLASS X 30 % 30 %

Geomagnetic Storms: Probabilities for significant disturbances in Earth's magnetic field are given for three activity levels: active, minor storm, severe storm
Updated at 2005 Sep 07 2204 UTC
0-24 hr 24-48 hr
ACTIVE 20 % 20 %
MINOR 05 % 05 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 25 % 25 %
MINOR 10 % 10 %
SEVERE 01 % 01 %

What's Up in Space -- 8 Sep 2005
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SOLAR FLARE: On Sept. 7th at 1740 UT (1:40 p.m. EDT), Earth-orbiting satellites detected a major X17-class solar flare coming from the sun's eastern limb: image. The blast caused a complete blackout of HF radio transmissions on the daylit side of Earth.

The source of the flare was returning sunspot 798 (see below), which sparked strong auroras in late August. Two weeks of quiet followed those storms while the sunspot transited the farside of the sun--but now it's back, and it's turning toward our planet again. Explosions later this week and next could produce more radio blackouts and some lovely September auroras.

Above: Sunspot 798 on Sept. 8th. Credit: Andreas Murner of Bavaria, Germany

LISTEN--RADIO BURSTS! In New Mexico, amateur astronomer Thomas Ashcraft recorded strong radio bursts during the flare: audio file. These slowly undulating signals, known as Type II radio bursts, are emitted by shocked gas at the leading edge of a coronal mass ejection (CME) racing away from the blast site. Use stereo headphones for best effect; the file plays 22.2 MHz in one ear, and 22.7 MHz in the other. [more]

MAGNETIC ARCHES: Sunspot 798, the source of yesterday's flare, has an impressive magnetic field. You can see it in this Sept. 7th picture from Jack Newton of Osoyoos, British Columbia:

The arches are magnetic force fields emerging from the sunspot below; they're filled with hot-glowing gas held together by magnetism. When these kinds of magnetic fields become unstable, they can collapse and explode--a solar flare! Forecasters estimate a 30% of another X-flare from sunspot 798 during the next 24 hours.

more images: from Gary Palmer of Los Angeles, CA; from Sean Walker of Methuen, Massachusetts; from Harald Paleske of Langendorf, Germany; from John Stetson of Falmouth, Maine; from Steve Rismiller of Milford, Ohio; from Andrew Chatman of Pittsford, NY;

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 are on a collision course with our planet, although astronomers are finding new ones all the time.

On 8 Sep 2005 there were 710 known Potentially
Hazardous Asteroids

August 2005 Earth-asteroid encounters



1992 UY4

August 8

16 LD

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

SOHO Farside Images of the Sun from SWAN and MDI.

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

The Sun from Earth -- daily images of our star 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.

Aurora Forecast --from the University of Alaska's Geophysical Institute

Daily Solar Flare and Sunspot Data -- from the NOAA Space Environment Center.

Lists of Coronal Mass Ejections -- from 1998 to 2001

What is an Iridium flare? See also Photographing Satellites by Brian Webb.

What is an Astronomical Unit, or AU?

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1999; 2000; 2001; 2002; 2003; 2004; Jan-Mar., 2005;

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


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

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