Solar Wind

speed: 368.4 km/s
2.7 protons/cm3
explanation | more data
Updated: Today at 2358 UT

X-ray Solar Flares

6-hr max:
B6 1105 UT Dec15
24-hr: B6 1105 UT Dec15
explanation | more data
Updated: Today at 1655 UT

Daily Sun: 15 Dec '04
There are no sunspots on the sun today. Image credit: SOHO/MDI

The Far Side of the Sun

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

Sunspot Number: 18
What is the sunspot number?
Updated: 14 Dec 2004

Interplanetary Mag. Field
Btotal: 6.1 nT
2 nT south
explanation | more data
Updated: Today at 1656 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole might buffet Earth's magnetic field on Dec. 16th. Image credit: SOHO's 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 Dec 14 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 2004 Dec 14 2200 UTC
0-24 hr 24-48 hr
ACTIVE 15 % 20 %
MINOR 01 % 05 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 15 % 30 %
MINOR 01 % 10 %
SEVERE 01 % 05 %

What's Up in Space -- 15 Dec 2004
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Did you miss the intense auroras of Nov. 7th? Next time get a phone call. Sign up for SpaceWeather PHONE.

SOLAR ACTIVITY: There are no big spots on the sun today, but that doesn't mean solar activity is low. Astronomers are monitoring some impressive prominences spilling over the sun's eastern limb. Witness this photo contributed by Gary Palmer of Los Angeles, California:

more images: from Andy Dodson of Taranaki, New Zealand; from Monty Leventhal of Sydney. Australia; from Didier Favre of Los Angeles, California.

GOOD GEMINIDS: "For once, a meteor shower did better than predicted," says meteor forecaster Bill Cooke of NASA's Marshall Space Flight Center.

According to observations published today by the International Meteor Organization, peak Geminid rates exceeded 160 meteors per hour on Monday, Dec. 13th. Click here to view a comparison of those data with Cooke's forecast.

Right: Frankie Lucena of Cabo Rojo, Puerto Rico, photographed this fireball during the peak of the Geminid meteor shower. "The meteor was very bright and its debris stood plastered in the sky for several seconds," says Lucena.

Geminid Meteor Gallery

COMET MACHHOLZ: "The comet was immediately visible to the naked eye," says Jimmy Westlake, who took this picture (a 5-min. exposure) of Comet Machholz from Colorado on Dec. 11th:

Comet Machholz (C/2004 Q2) has been nearing Earth for weeks, brightening day by day, and now it looks like a fuzzy 5th-magnitude star near the feet of Orion. Look for it in the southeastern sky a few hours after sunset: sky map. Astronomers expect Comet Machholz to reach peak brightness (3rd or 4th magnitude) in January 2005--an easy target for Christmas telescopes. [ephemeris]

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 15 Dec 2004 there were 654 known Potentially
Hazardous Asteroids
Nov.-Dec. 2004 Earth-asteroid encounters



2004 TP1

Nov. 2

13 LD

2004 UE

Nov. 9

10 LD

2004 RZ164

Dec. 8

7 LD

2004 VW14

Dec. 24

5 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


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