SPACE WEATHER
Current
Conditions

Solar Wind
speed: 459.2 km/s
density: 6.3 protons/cm³
explanation | more data
Updated: Today at 2256 UT

X-ray Solar Flares
6-hr max: B1 2200 UT Apr10
24-hr: B4 0130 UT Apr10
explanation | more data
Updated: Today at 2245 UT

Daily Sun: 10 Apr '04
Sunspot 588 continues to decay and no longer poses much of a threat for solar flares. Image credit: SOHO

The Far Side of the Sun

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

Sunspot Number: 18
What is the sunspot number?
Updated: 09 Apr 2004

Interplanetary Mag. Field
B_total: 9.1 nT
B_z: 0.6 nT north
explanation | more data
Updated: Today at 2256 UT

Coronal Holes:

A solar wind gust from the indicated coronal hole could buffet Earth's magnetic field tonight. Image credit: SOHO Extreme UV Imager

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.

April 2004 Earth-asteroid encounters

ASTEROID		MISS DISTANCE	MAG.
2001 HB	Apr. 4	36 LD	19
2004 FY31	Apr. 11	12 LD	19
1999 DJ4	Apr. 20	23 LD	19
2003 YT1	Apr. 30	29 LD	14

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.

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 Soft 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