Clear Sky Chart
The Observer's Guide to Seeing.
CRWS Jet Stream
Report of Jet Stream Location, critical to observing.
Posts hourly images of our Sun in multiple bands which in turn yield different atmospheric depths.
Sun / Moon Rise-Set
Sunset Times and Moon Phases.
Amateur Telescope Optics
Lots of Technical Information about Optics.
An independent, student-based organization which promotes the exploration and development of space.