What could be happening on the Sun right now, and why is it important?
Event	Examples	Communications, navigation, & radio difficulties?	Damage satellites?	Threaten power grids?	Danger to astronauts or pilots?	Cause flow of currents in pipelines?	Generate auroras?	Affect racing pigeons or other animals?	Contribute to global warming?
Sunspots	Sunspot cluster								maybe???
Coronal Mass Ejections (CMEs)	CME (movie)	X	X	X	X	X	X	Anything over 150 in geomagnetic activity, or 4 in local 'K' index figures
Solar flares	X-ray Flare	only X and M class flares	only X and M class flares
Strong solar winds	Solar Wind	X	X	X	X	X	X	X
Filaments/prominences	Filament Prominence
Coronal Holes	Coronal hole
Change in solar irradiance								X	X
Eclipse	Solar eclipse							X
Sungrazing comets	SOHO Comets
Planetary alignments	2 planets
Mercury or Venus Transit	Mercury Transit (movie)

Solar disturbances can cause:

1. Geomagnetic Storms -- disturbances in the geomagnetic field caused by gusts in the solar wind that blows by Earth.
   Causes: Coronal Mass Ejections (CMEs)
   Affects: power systems, spacecraft operation, radio propagation, navigation, migratory animals, auroras
   Scale & measurements: Geomagnetic Storm Scale ("A" index values range from 0 to 400 Nanoteslas; K & Kp index values range from 0 to 9, anything over 5 can have effects on Earth)

2. Solar Radiation Storms -- elevated levels of radiation that occur when the numbers of energetic particles increase.
   Causes:
   Affects: radiation hazard to astronauts & high-flying planes, satellite operations, communications systems
   Scale & measurements: Solar Radiation Storm Scale (proton/ion flux levels; anything over 10 can have affects on Earth)

3. Radio Blackouts -- disturbances of the ionosphere caused by X-ray emissions from the Sun.
   Causes: M-class and X-class solar flares
   Affects: high frequency radio, navigation systems
   Scale & measurements: Radio Blackouts Scale (based on x-ray brightness; only M- and X-class flares can affect Earth)