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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: 605.3 km/s
3.2 protons/cm3
explanation | more data
Updated: Today at 2245 UT

X-ray Solar Flares

6-hr max:
C3 1820 UT Jan04
24-hr: C3 1525 UT Jan04
explanation | more data
Updated: Today at 2245 UT

Note: Because of the holidays, daily images of the sun from SOHO are temporarily unavailable.

Daily Sun: 26 Dec '03
Sunspot 528 poses a threat for M-class solar flares. Image credit: SOHO MDI

The Far Side of the Sun

This holographic image reveals a substantial sunspot group on the far side of the sun. Image credit: SOHO/MDI

Sunspot Number: 65
What is the sunspot number?
Updated: 03 Jan 2004

Interplanetary Mag. Field
Btotal: 8.2 nT
3.8 nT south
explanation | more data
Updated: Today at 2245 UT

Coronal Holes:

There are no big coronal holes on the Earth-facing side of the sun today. 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 2004 Jan 04 2200 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 40 % 40 %
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 2004 Jan 04 2200 UTC
0-24 hr 24-48 hr
ACTIVE 35 % 35 %
MINOR 15 % 15 %
SEVERE 10 % 10 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 40 % 40 %
MINOR 20 % 20 %
SEVERE 10 % 10 %

What's Up in Space -- 4 Jan 2004
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MARS: Tonight is a good night to look at Mars. NASA's six-wheeled rover Spirit landed there less than 24 hours ago, in a place called Gusev Crater. Spirit is beaming some wonderful images to Earth--you've probably seen them on TV or on the web. Are you ready for a break from screens? When the sun sets tonight, step outside and face south (or north, if you live in the southern hemisphere). Butterscotch-colored Mars is the brightest star in that direction. [sky map]

EARTH AT PERIHELION: Earth's orbit around the sun isn't a perfect circle, it's an ellipse. One side is closer to the sun (147.5 million km) than the other (152.6 million km). Today, January 4th, we're at the closest point, known to astronomers as perihelion. (continued below)

When Earth is at perihelion, the sun looks a little bigger than usual, as shown in the composite image, above, from Luis Carreira of Leiria, Portugal. He took the two pictures from opposite ends of Earth's orbit: perihelion and aphelion. Sunlight falling on Earth at perihelion is 3.5% stronger than the year-long average. Northern snow doesn't melt, however, because seasons are shaped primarily by the tilt of Earth's spin axis, not the eccentricity of its orbit.

FIRST AURORAS: A solar wind stream has been buffeting Earth's magnetic field this weekend and causing mild geomagnetic storms. On Jan. 3rd, Yuichi Takasaka saw these auroras, the first of 2004, above the Kincolith River in British Columbia:

More such high-latitude auroras are possible in the days ahead as Earth continues its passage through the solar wind stream.

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 4 Jan 2004 there were 562 known Potentially
Hazardous Asteroids

December 2003 Earth-asteroid encounters


2003 YS17

Jan 14

14 LD

2001 BE10

Jan 15

23 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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