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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: 562.4 km/s
1.3 protons/cm3
explanation | more data
Updated: Today at 2256 UT

X-ray Solar Flares

6-hr max:
A2 1750 UT Jul28
24-hr: A7 1315 UT Jul28
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 28 Jul '06

Sunspot 901 poses no threat for solar flares. Credit: SOHO/MDI

Sunspot Number: 23
What is the sunspot number?
Updated: 27 Jul 2006

Far Side of the Sun

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

Interplanetary Mag. Field
Btotal: 3.2 nT
1 nT south
explanation | more data
Updated: Today at 2257 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole should reach Earth on July 31st or August 1st. 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 2006 Jul 28 2203 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 2006 Jul 28 2203 UTC
0-24 hr 24-48 hr
ACTIVE 20 % 15 %
MINOR 10 % 05 %
SEVERE 01 % 01 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 20 % 15 %
MINOR 10 % 05 %
SEVERE 01 % 01 %

What's Up in Space -- 28 Jul 2006
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AURORA WATCH: A high-speed solar wind stream hit Earth last night, sparking auroras over parts of Canada and some northern US states: gallery. The storm has subsided, but the solar wind is still blowing, raising the possibility of another storm tonight. Sky watchers should remain alert for auroras.

LUNAR IMPACTS: There's a meteor shower on the Moon tonight. Like Earth, the Moon is inside the Delta Aquarid meteoroid stream. Unlike Earth, however, the Moon has no atmosphere to shield it. Meteors on the Moon hit the ground and explode. (continued below)

"Keeping an eye on the Moon." Photo credit: Jimmy Westlake. July 27, 2006.

Some of the impact flashes might be visible from Earth. When the sun goes down tonight, train your telescope on the crescent Moon: sky map. Look left of the crescent where the lunar terrain is dark. Split-second flashes of light could signal Delta Aquarids hitting the ground. Amateur astronomers who wish to make scientifically meaningful observations, please click here for tips.

WHAT'S ON TOP? On July 22nd, "my wife kindly blocked out the sun, revealing a beautiful sun halo criss-crossed by contrails," says photographer Charlie Szabototh of Wiarton, Ontario. The question is, what's on top? The halo or the contrails? Look carefully at the image, then scroll down for the answer:

The contrails are on top. See the dark fringes to the left of the contrails? Those are contrail shadows, cast down on the icy cloud layer that makes the sun halo. "I always find contrail shadows counter-intuitive," notes atmospheric optics expert Les Cowley. "Somehow we expect objects we see in the air to be in front of the clouds. These bright contrails, however, are not beneath the clouds; they are above them as their shadows reveal."

more images: from Bruno Nolf of Otegem, Belgium; from Dave Yates of Bishton, South Wales; from Riccardo Di Nasso of Pisa, Italy; from Laurent Laveder of Bretagne, France; from Martin Mc Kenna of Northern Ireland; from Rodrigo Roesch of Zion, Illinois;

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 is on a collision course with our planet, although astronomers are finding new ones all the time.

On 28 Jul 2006 there were 796 known Potentially
Hazardous Asteroids

July 2006 Earth-asteroid encounters




2004 XP14

Jul 3

1.1 LD


600 m
2006 BQ6

Jul 29

14 LD


500 m
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

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.

Lists of Coronal Mass Ejections -- from 1998 to 2001

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006;

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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