Astronomical Terms

• USNO: Rise, set and twilight definitions by U.S. Naval Observations?
• International Comet Quarterly: Definitions and explanations of comet and astronomical terms/
• NOVAC: Glossary of terms used by the Northern Virginia Astronomy Club.  Chinese Astronomy: Solar Terms and the Chinese Calendar
• Sea and Sky’s Astronomy Resources:  Non-technical explanations of astronomical terms. 
• SkyEye Online Glossary: Definitions of the most common words used in astronomy, astrophysics, cosmology, and space exploration.
• Science U: Terms used in the S.U. observatory.

 Daylength-Charts 

• Daylight Chart: Free, downloadable program that allows users to display, customize, save and print, sunrise and sunset charts for a whole year at any location in the world.
• Day and Night World Map: See what parts of the Earth are experiencing day light and in what parts it is nighttime.

Moon Phases and Positions

• Phases of the moon: Dates of the primary phases of the moon and a lunar eclipse calculator from the U.S. Naval Observatory
• NASA Eclipse Website: Tables showing phases of the moon from 1999 to 4000. National Institute of Environmental Health Sciences Kids’ pages on space and especially the moon. 3-D Images and descriptions of the phases of the moon from the Smithsonian National Air and Space Museum. Interactive display of the phases of the moon. The moon phases according to time and location/ Convert from dates found on the Western calendar to the Chinese calendar. Includes links to other Chinese Lunar sites as well.
• Space & Earth Science: Learn about the moon and how the Earth interacts with it.
• Discover the Moon: A guide to the phases of the moon.
• Lunar Phases Applet: Use this tool to help track the movements of the moon and see which the moon is currently in.
• Lunar Calendar: Learn more about the lunar phases throughout the year.
• Western-Chinese Calendar Converter: A tool that can be used to better understand the western and Chinese lunar calendars.
• Moon Connection: Understanding what causes the phases of the moon.

 Solar Energy Information

• Solar Basics: How solar energy works and where it is found, especially written for children.
• Energy Sources: Information on solar energy from the United States Department of Energy.
• Solar Energy: Benefits of solar energy including studies and maps presented by the United States Department of the Interior Bureau of Land Management.
• Solar Research: Information on research in the field of Solar Energy provided by the National Renewable Energy Laboratory.
• Solar Energy Sites: List of several sites pertaining to Solar Energy.
• Using Solar Energy: Describes how solar energy can be used on farms and ranches to meet or supplement their energy needs.

Sun Position (Azimuth and Altitude)

• Altitude and Azimuth: Basic definition of the terms including diagrams. Solar Position Calculator: Use to calculate solar zenith angle, declination, Julian day, equation of time, hour angle, instantaneous and daily extraterrestrial radiation values, and sunrise and sunset times from the University of Oregon Solar Radiation Monitoring Laboratory.
• MIDC SPA Calculator: Use to compute the solar position from universal time and location.
• Azimuth/Altitude Demonstrator: Shows how altitude and azimuth define an object's position in the sky.
• The Solar Altitude and Azimuth Calculator: An interactive tool to calculate position, includes Mazria’s sun path diagram

Sunrise/Sunset Calculators

• Sunrise Calculator: National Oceanic & Atmospheric Administration Sunrise Calculator
• Local Calculations: Local sunrise and sunset calculations from the FCC.
• WxCam Sunrise/Sunset/Twilight Calculator: Calculate sunrise, sunset, and civil/nautical twilight for any place on Earth by entering Latitude and Longitude .
• Sunset Computer: Compute Sunrise, Sunset & Twilight For Cities & Airports Worldwide With Local Time Zones.
• GAISMA: Interactive map that provides sunrise, sunset, dusk and dawn times for thousands of locations all over the world

Sun Calendars

• Sun/Moon Calendar: View the Sun/Moon Calendar for a one year period.
• Aztec Calendar: Images and description of The Sun Stone.
• The Sundial: Explanation of how a sundial works and simple directions on how to construct one.