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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: 657.2 km/s
3.6 protons/cm3
explanation | more data
Updated: Today at 2246 UT

X-ray Solar Flares
6-hr max:
B5 2035 UT Apr27
24-hr: B7 0445 UT Apr27
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 27 Apr '07

Although sunspot 953 is large, its magnetic field is uncomplicated. This means it poses little threat for strong solar flares. Credit: SOHO/MDI

Sunspot Number: 17
What is the sunspot number?
Updated: 26 Apr 2007

Far Side of the Sun

This holographic image reveals a sunspot on the farside of the sun--due to arrive on the Earthside about 3 days from now. Image credit: SOHO/MDI

Interplanetary Mag. Field
Btotal: 7.7 nT
6.8 nT south
explanation | more data
Updated: Today at 2247 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole should hit Earth on April 28th. 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 2007 Apr 27 2203 UTC
FLARE 0-24 hr 24-48 hr
CLASS M 15 % 15 %
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 2007 Apr 27 2203 UTC
0-24 hr 24-48 hr
ACTIVE 45 % 30 %
MINOR 25 % 15 %
SEVERE 10 % 05 %

High latitudes
0-24 hr 24-48 hr
ACTIVE 45 % 30 %
MINOR 30 % 20 %
SEVERE 15 % 10 %

What's Up in Space -- 27 Apr 2007
Subscribe to Space Weather News

What's the name of that star? Where's Saturn? Get the answers from mySKY--a fun new astronomy helper from Meade.

AURORA WATCH: Northern sky watchers should be alert for auroras tonight. Earth is entering a solar wind stream, and this could cause a geomagnetic storm.

SOLAR CYCLE NEWS: This week in Boulder, Colorado, a group of leading solar physicists met to compare and discuss their predictions for the next solar maximum. On April 25th they held a press conference and announced ... a split decision. One camp holds that Solar Cycle 24 will be intense and peak in 2011; a second group predicts a much weaker maximum in 2012.

As a community, solar physicists are still undecided on the best way to predict solar activity. The plot, above, is a summary of 40 different forecasts, none of which agree in detail. The confusion won't last forever. As Cycle 24 unfolds, the sun itself will tell us which is correct.

Researchers were able to agree on one thing: Solar activity is entering a period of deep minimum. Based on declining sunspot numbers and other factors, the cycle should hit rock bottom in March 2008 plus or minus six months.

SUNSPOT WATCH: Yesterday at sunset, photographer Mila Zinkova of San Francisco went to the beach to see sunspot 953, "but I had a hard time to finding it," she says. Seagulls kept getting in the way:

Photo details: Canon XTI, 300 mm Canon Lens, Landscape mode

The strange shape of the sun is a mirage, caused by multiple temperature inversion layers just above the sea surface. This distortion, as much as the intervening gulls, makes sunspot 953 difficult to see. Yet it is there, four times wider than Earth and wonderful to behold through backyard solar telescopes. Browse the images, below:

Sunspot 953: from Peter Paice of Belfast, Northern Ireland; from Robert Arnold on the Isle of Skye, Scotland; from Emiel Veldhuis of Zwolle, the Netherlands; from Howard Eskildsen of Ocala, Florida.

NOCTILUCENT CLOUDS: NASA's AIM spacecraft left Earth this week on a mission to study mysterious noctilucent clouds. These clouds, which glow electric blue and appear only at night, were first noticed in the 19th century over polar regions. In recent years, they've brightened and spread to lower latitudes. What causes noctilucent clouds? Theories range from space dust to global warming. AIM will scrutinize the clouds from orbit to find out what they may be telling us about our planet.

Noctilucent Cloud Photo Gallery
Visit the gallery for observing tips and sample camera settings.

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 27 Apr 2007 there were 859 known Potentially
Hazardous Asteroids

April 2007 Earth-asteroid encounters




2006 VV2

Mar. 31

8.8 LD


2 km
2007 FY20

Apr. 2

5.3 LD


50 m
2007 DS84

Apr. 14

16 LD


325 m
2007 GU1

Apr. 16

2.1 LD


45 m
2007 HA

Apr. 17

6.5 LD


300 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.

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 -- from the National Solar Data Analysis Center

Recent Solar Events -- a summary of current solar conditions from

What is the Magnetosphere?

The Lion Roars -- visit this site to find out what the magnetosphere sounds like.

List of Potentially Hazardous Asteroids -- from the Harvard Minor Planet Center.

Observable Comets -- from the Harvard Minor Planet Center.

Real-time Solar Wind Data -- from NASA's ACE spacecraft.

How powerful are solar wind gusts? Not very! 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 1996 to 2006

Mirages: Mirages in Finland; An Introduction to Mirages;

NOAA Solar Flare and Sunspot Data: 1994, 1995, 1996, 1997, 1998, 1999; 2000; 2001; 2002; 2003; 2004; 2005; Jan-Mar 2006; Apr-Jun 2006; Jul-Sep 2006; Oct-Dec 2006.

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

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