International Astronomical Union (IAU)
Promotes and safeguards the science of astronomy in all its aspects through international cooperation. The sole internationally recognised authority for assigning designations to celestial bodies and surface features on such bodies.
www.iau.org
International Dark-Sky Association
Nonprofit membership-based organization that aims stop the adverse environmental impact of light pollution and space debris.
www.darksky.org
Astronomical Society of the Pacific
International nonprofit organization offering educational programs and products, research publications, and membership benefits.
www.astrosociety.org
Royal Astronomical Society
Publishes journals, awards medals, fellowships and prizes. Houses one of the most comprehensive libraries and archives in the world.
www.ras.org.uk
Texas Astronomical Society of Dallas
Chartered in 1955 to promote the study of astronomy and related fields and to pursue observation and construction of instruments as a hobby.
www.texasastro.org
Planetary Studies Foundation
Nonprofit sponsoring educational astronomy programs in Palatine, IL. Links to astronomy articles and tutorials online.
www.planets.org