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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: 391.4 km/s
4.6 protons/cm3
explanation | more data
Updated: Today at 2216 UT

X-ray Solar Flares

6-hr max:
B2 1805 UT Sep29
24-hr: B2 1805 UT Sep29
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 28 Sep '04
Tiny sunspot 675 poses no threat for strong solar flares. Image credit: Big Bear Solar Observatory.

NOTE: SOHO (the Solar and Heliospheric Observatory) is passing through a telemetry keyhole. Daily Sun and other images from SOHO will return to when the spacecraft emerges from the keyhole on October 1st.

Sunspot Number: 22
What is the sunspot number?
Updated: 28 Sep 2004

Interplanetary Mag. Field
Btotal: 4.1 nT
1.4 nT south
explanation | more data
Updated: Today at 2217 UT

Coronal Holes:

There are no big coronal holes on the Earth-facing side of the sun today. Image credit: NOAA's Solar X-ray Imager (SXI)


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 2004 Sep 29 2200 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 2004 Sep 29 2200 UTC
0-24 hr 24-48 hr
ACTIVE 20 % 20 %
MINOR 10 % 10 %
SEVERE 05 % 05 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 30 % 30 %
MINOR 10 % 10 %
SEVERE 05 % 05 %

What's Up in Space -- 29 Sep 2004
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SOLAR OUTLOOK: Solar activity is very low and it should remain low for at least the next three days. Unless something unexpected happens, bright auroras are unlikely this week.

Never miss another meteor shower, or lunar eclipse, or space station flyby. Sign up for Spaceweather PHONE.

ASTEROID FLYBY: A big asteroid named 4179 Toutatis is flying past Earth today. This space rock is shaped like a peanut about 3 miles long and it tumbles like a badly thrown football. Astronomers say there's no danger of a collision, but they'll be monitoring it closely anyway.

All asteroids glow by means of reflected sunlight. Toutatis is about as bright as a 9th magnitude star. It's an easy target for backyard telescopes--but only in the southern hemisphere. Observers in Australia and New Zealand will have a good view of Toutatis gliding 1o from the bright star Alpha Centauri. [ephemeris] [finder charts]

Right: 4179 Toutatis on Sept. 27th, photographed by Alberto Quijano Vodniza and Mario Rojas at the University of Nariño Observatory in Columbia. Click to view a full-sized (2 MB) movie.

During previous near-Earth flybys, astronomers pinged the space rock using NASA radars. They pinpointed Toutatis' orbit, showing that it poses no danger to Earth for centuries at least, and mapped Toutatis' bizarre surface. Radar observations again this year aim to measure Toutatis' Yarkovsky acceleration.

HARVEST MOON: If you can't sleep tonight because there's a bright light beaming through your bedroom window ... blame the Harvest Moon--the first full moon of autumn. The Harvest Moon got its name from farmers who, long ago, relied on its light to gather autumn crops after dark. In Pukalani, Maui, Rob Ratkowski took this picture of the brilliant Harvest Moon on Sept. 28th:

The Harvest Moon setting over the West Maui Mountains.

EDUCATORS: Would you like to get lesson plans and classroom activities about events in the night sky? Here's one about the Harvest Moon. Sign up for Sky Calls and we'll send you up-to-date lessons three or four times a month.

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 29 Sep 2004 there were 618 known Potentially
Hazardous Asteroids

Sept. 2004 Earth-asteroid encounters


2003 UX34

Sept. 9

22 LD

2004 JA27

Sept. 10

23 LD

1998 OX4

Sept. 14

25 LD


Sept. 29

4 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.

Vandenberg AFB missile launch schedule.

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; Jan-Mar., 2004;

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


Editor's Note: This site is sponsored by Science@NASA. Space weather and other forecasts that appear here are formulated by Dr. Tony Phillips. They are not guarantees of space weather or other celestial activity.

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