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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: 430.5 km/s
2.0 protons/cm3
explanation | more data
Updated: Today at 2244 UT

X-ray Solar Flares

6-hr max:
C1 2015 UT Dec17
24-hr: C8 0310 UT Dec17
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 17 Dec '03
None of these small sunspots pose a threat for strong solar flares. Image credit: SOHO MDI

The Far Side of the Sun

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

Sunspot Number: 71
What is the sunspot number?
Updated: 16 Dec 2003

Interplanetary Mag. Field
Btotal: 3.7 nT
1.4 nT south
explanation | more data
Updated: Today at 2245 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole could reach Earth on Dec. 21st. Image credit: SOHO Extreme UV Telescope.


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 2003 Dec 17 2200 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 05 % 05 %
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 2003 Dec 17 2200 UTC
0-24 hr 24-48 hr
ACTIVE 35 % 45 %
MINOR 10 % 20 %
SEVERE 01 % 05 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 35 % 40 %
MINOR 15 % 25 %
SEVERE 05 % 10 %

What's Up in Space -- 17 Dec 2003
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SUNSPOTS: The Earth-facing side of the sun is nearly blank. Only a few small sunspots pepper the solar disk. But the farside of the sun is a different story. Holographic images reveal what may be a large sunspot group there. If it persists, the 'spot would appear on the sun's eastern limb on or about Dec. 22nd.

DUST STORM ON MARS: Although Mars has been receding from Earth since August, it's still big and bright enough for backyard telescopes to reveal features on its surface. Lately, amateur astronomers have been seeing something new: bright clouds of dust spreading around the planet.

Above: Martian dust clouds on Dec. 16th, photographed by Don Parker of Coral Gables, Florida. See also images of Mars on Dec 13th and 14th from Don Parker; on Dec. 15th from Ed Grafton; and Dec. 16th from Joel Warren.

A curious side-effect of the storm is the increasing brightness of Mars. "Mars was about 0.17 magnitudes brighter on Dec. 15th," says ALPO executive director Richard Schmude, Jr. "This increase is due to [sunlight reflected by] dust. Polarization measurements also indicate the presence of some dust."

Dust storms on Mars sometimes grow so large that they encircle the entire planet. Will this one? No one knows. But with three space probes (Beagle 2, Spirit & Opportunity) set to land on Mars in the coming weeks, astronomers will be watching carefully to see what happens.

DAYTIME JUPITER: Jupiter is bright enough to see in broad daylight--if you know where to look. On Dec. 16th the quarter Moon and Jupiter were only a few degrees apart, so sky watchers were able to find it using the bright moon as a guide. For instance, Wren Keller of Tucson, Arizona, took this picture of Jupiter through a 10-inch telescope at 9 o'clock in the morning.

You don't need a big telescope, however, to see planets during the day. Binoculars work fine. Bright Venus and Jupiter are easy targets when the Moon is nearby. Saturn and Mars are possible, too. It's fun and a little surprising to see these planets pop out from the blue when you happen across them.

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 17 Dec 2003 there were 549 known Potentially
Hazardous Asteroids

November 2003 Earth-asteroid encounters


2003 UC20

Dec 2

32 LD

2003 XJ7

Dec 6

0.4 LD

2003 WY25

Dec 12

10 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.

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 Soft 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; Jan-Mar., 2003; Apr-Jun., 2003;

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 should not be construed as guarantees of space weather or other celestial activity.

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