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 --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.
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;
GLOSSARY | SPACE WEATHER TUTORIAL