名稱	網址
NASA's Comet Observation Page	http://encke.jpl.nasa.gov/
NASA solar-eclipse bulletins	http://umbra.nascom.nasa.gov/sdac.html
Astro-Mart	http://www.astromart.com/
Comets and Meteor Showers	http://comets.amsmeteors.org
ATM Page	http://www.atmpage.com/
Visual Limiting Magnitude Estimation	http://www.seds.org/billa/lm/rjm.html