Featured VIDEO: Conversations at KCTS 9: Neil Degrasse Tyson

The International Astronomical Union (IAU), founded in 1919, promotes and safeguards the science of astronomy in all its aspects through international cooperation. Its individual members are professional astronomers from all over the world, at the Ph.D. level, and active in professional research and education in astronomy. The IAU serves as the internationally recognized authority for assigning designations to celestial bodies and surface features on them. It has 9647 Individual Members in 86 countries worldwide

The American Astronomical Society (AAS), established 1899, is the major organization of professional astronomers in North America. The membership (~6,500) also includes physicists, mathematicians, geologists, engineers and others whose research interests lie within the broad spectrum of subjects now comprising contemporary astronomy.

The Royal Astronomical Society in the U.K. received its royal charter in 1831 and now has over 3000 members, about one-third residing outside the U.K. The European Astronomical Society is an association founded under the Swiss Civil Code in 1990.