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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: 561.0 km/s
1.8 protons/cm3
explanation | more data
Updated: Today at 2243 UT

X-ray Solar Flares

6-hr max:
M4 1750 UT Jan17
24-hr: M4 1750 UT Jan17
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 17 Jan '04
Sunspots 537 and 540 pose a threat for M-class solar flares. Image credit: SOHO/MDI

The Far Side of the Sun

This holographic image reveals no big sunspots on the far side of the Sun. Image credit: SOHO/MDI

Sunspot Number: 68
What is the sunspot number?
Updated: 16 Jan 2004

Interplanetary Mag. Field
Btotal: 6.4 nT
0.3 nT north
explanation | more data
Updated: Today at 2247 UT

Coronal Holes:

Earth is inside a solar wind stream flowing from the indicated coronal hole. 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 17 2200 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 20 % 20 %
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 17 2200 UTC
0-24 hr 24-48 hr
ACTIVE 25 % 20 %
MINOR 10 % 05 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 30 % 25 %
MINOR 15 % 10 %
SEVERE 05 % 05 %

What's Up in Space -- 17 Jan 2004
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MARS & VENUS: This weekend Mars (190 million miles) and Venus (180 million miles) are about the same distance from Earth, yet one is spectacularly brighter than the other. Why? Because both shine by reflected sunlight and Venus is much closer to the Sun. Also, Venus' acid clouds are more reflective (~70%) than Mars' dusty surface (~10%). See for yourself. Go outside around sunset and look southwest. Venus is dazzling near the horizon; Mars much dimmer high in the sky. [sky map] [picture]

COLD SNAP: When the temperature drops and ice crystals fill the air, be alert for strange pillars of light--during the day and at night. In Niagra Falls, New York, where the thermometer registered -10o F at 2 o'clock in the morning, Brian Larmay took this picture of colorful pillars rising up from the ground: (continued below)

"What an amazing sight," says Larmay. "The show was so intense that a lot of people called these in as UFOs."

Nighttime light pillars like these are caused by city lights glinting through plate shaped ice crystals normally found only in high clouds. On this cold night, however, the crystals were floating close to the ground. The pillars look like auroras, but they are not. Says Larmay, "I treated them like auroras photographically" with pleasing results. More images: #1, #2.

AURORA WATCH: Earth is inside a solar wind stream flowing from a coronal hole on the sun. High-latitude sky watchers should be alert for auroras tonight. Yuichi Takasaka recorded these dancing auroras over Yellowknife, Northwest Territories, Canada on January 16th. [gallery]

MERCURY: This weekend is a good time to see the planet Mercury. Look east at sunrise for a bright pink star close to the horizon. On Jan. 19th Mercury will appear right beside the slender crescent moon. Mark your calendar! [sky map]

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 Jan 2004 there were 565 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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