SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

SPACE WEATHER
Current
Conditions

Solar Wind
speed: 471.0 km/s
density: 2.5 protons/cm³
explanation | more data
Updated: Today at 2121 UT

X-ray Solar Flares
6-hr max: A4 1615 UT Apr20
24-hr: B1 0010 UT Apr20
explanation | more data
Updated: Today at 2120 UT

Daily Sun: 20 Apr '05

These small sunspots pose no threat for strong solar flares. Credit: SOHO/MDI

Sunspot Number: 43
What is the sunspot number?
Updated: 19 Apr 2005

Far Side of the Sun

This holographic image reveals one sunspot group on the far side of the Sun. Image credit: SOHO/MDI

Interplanetary Mag. Field
B_total: 6.0 nT
B_z: 1.1 nT north
explanation | more data
Updated: Today at 2126 UT

Coronal Holes:

A solar wind stream flowing from the indicated coronal hole could hit Earth's magnetic field on April 22nd or 23rd. Image credit: SOHO Extreme Ultraviolet Telescope

SPACE WEATHER
NOAA
Forecasts
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 2005 Apr 19 2206 UTC

FLARE	0-24 hr	24-48 hr
CLASS M	05 %	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 2005 Apr 19 2206 UTC
Mid-latitudes

	0-24 hr	24-48 hr
ACTIVE	20 %	20 %
MINOR	10 %	10 %
SEVERE	01 %	01 %

High latitudes

	0-24 hr	24-48 hr
ACTIVE	25 %	25 %
MINOR	10 %	10 %
SEVERE	05 %	01 %

What's Up in Space -- 20 Apr 2005
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LYRID METEORS: The annual Lyrid meteor shower peaks this Friday morning, April 22nd, when Earth glides through a stream of debris trailing Comet Thatcher. Go outside two hours before dawn and watch the sky until sunrise. You might see a dozen or more shooting stars coming from the vicinity of the bright star Vega. [sky map]

SOLAR ACTIVITY: There aren't any big 'spots on the sun today, but that doesn't mean solar activity is nil. Amateur astronomers have been watching some gigantic prominences leap over the sun's limb. "The sun put on a fantastic show at the Northeast Astronomy Forum," says Greg Piepol, who took this picture on April 17th:

more images: from Monty Leventhal of Sydney, Australia; from John Stetson of Falmouth, Maine; from Didier Favre of Los Angeles, California;

April 8th Solar Eclipse Gallery

LUNAR ECLIPSE: Mark your calendar: there's going to be a lunar eclipse on April 24th. It's a "penumbral eclipse," which means the Moon only skims the pale outer fringes of Earth's shadow.

Above: The Moon glides through Earth's shadow on April 24th. Animation credit: Larry Koehn.

Penumbral eclipses are notoriously difficult to observe. Nevertheless, a subtle yet distinct shading should be visible across the northern half of the Moon during greatest eclipse, around 09:55 UT. For North Americans, that's Sunday morning at 2:55 a.m. PDT (5:55 a.m. EDT). [More]

EXTRA: What would this eclipse look like if you were standing on the Moon? Get the answer from Science@NASA.

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 20 Apr 2005 there were 681 known Potentially
Hazardous Asteroids Mar.-Apr. 2005 Earth-asteroid encounters

ASTEROID	DATE (UT)	MISS DISTANCE	MAG.
2005 FN	Mar. 18	0.4 LD	14
2005 FA	Mar. 19	2.3 LD	17
2005 ER70	Mar. 19	9.2 LD	19
2005 EU2	Apr. 5	6.2 LD	18
2005 EE169	Apr. 6	5.9 LD	18

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 lmsal.com.

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

GLOSSARY | SPACE WEATHER TUTORIAL