The Royal Observatory of Belgium (French: Observatoire Royal de Belgique; Dutch: Koninklijke Sterrenwacht van België; English: Royal Observatory of Belgium) is an astronomical observatory in Belgium, located in Keller, the research areas include astronomy and astrophysics, solar physics, seismology, etc. In 1981, it became the global sunspot data center.

The Union Radio-Scientifique Internationale (French: l'Union Radio-Scientifique Internationale; abbreviated as URSI), a member of the International Council for Science, was founded in 1919 as a non-governmental academic organization in the field of international radio science.