The International Year of Astronomy 2009 (IYA2009) is a year-long celebration of astronomy, taking place in 2009 to coincide with the 400th anniversary of the first recorded astronomical observations with a telescope by Galileo Galilei and the publication of Johannes Kepler's Astronomia nova in the 17th century. The Year was declared by the 62nd General Assembly of the United Nations. A global scheme, laid out by the International Astronomical Union (IAU), has also been endorsed by UNESCO—the UN body responsible for Educational, Scientific and Cultural matters. The opening ceremony was held in Paris on January 15–16, 2009. IYA2009 is scheduled to include numerous global projects and public events. The IAU also released a book and movie on the history of the telescope for this event.

The International Year of Astronomy (IYA2009) celebrates the first astronomical use of the telescope by Galileo - a momentous event that initiated 400 years of astronomical discoveries and triggered a scientific revolution which profoundly affected our worldview. Now telescopes on the ground and in space explore the Universe, 24 hours a day, across all wavelengths of light.

One the major source of astronomical information is radio astronomy. Radio astronomy does not involve the transmission of radio waves in the frequency bands allocated for its operation, and cannot cause harmful interference to other services. On the other hand, the received cosmic signals are usually extremely weak, and transmissions of other services can interfere with such signals. That is why the International Telecommunication Union (ITU), a specialized agency of the United Nations and the steward of the global framework for radio spectrum and satellite orbits, is very much involved in development and operation of the radio astronomy service.

ITU main activities related to radio astronomy, are the follows:

• ITU through its Radiocommunication Sector (ITU-R) provides such essential resources as radio-frequency spectrum and orbit resources for the radio astronomy service (RAS);
   

• ITU-R develops and approves international treaties (the Radio Regulations) and voluntary standards (ITU-R Recommendations) that establish the basis for the development and free of interference operation of radio astronomy stations on the Earth and in the space;
   

• ITU-R Radiocommunication Bureau carries out electromagnetic compatibility analysis, identifies the probable sources of interference and applies Radio Regulation procedures in order to protect radio astronomy stations;
   

• ITU-R Study Group 7 (Science Service) and Radiocommunication Assemblies (RAs) consider and approve and recommendations on the use of radio spectrum and protection of radio astronomical stations from interference included in Radio Astronomy (RA) Series of ITU-R Recommendations;
   

• Successive ITU World Radiocommunication Conferences (WRCs) have taken into account the needs of radio astronomy service to ensure the availability and protection of radio-frequency bands for radio astronomical observation tools. For example, the last WRC-07 approved Resolution 739 (Rev.WRC-07) 'Compatibility between the radio astronomy service and the active space services in certain adjacent and nearby frequency bands';
   

• in accordance with WRC-07 decisions the Radiocommunication Study Groups carries out the further studies  and develop of ITU-R Recommendations relevant to the use of radio astronomy;
   

• ITU-R has a special Working Party “Radio Astronomy” studying all related matters and preparing drafts of ITU-R standards. Working Party 7D on 'Radio Astronomy' currently carries out new studies on radio quiet zones for radio astronomy. They include: study the characteristics of existing radio quiet zones, protection of these zones, characteristics of the instruments of the radio astronomy service that have stimulated the development of radio quiet zones, and characteristics of the electromagnetic environment stimulated the development of radio quiet zones;
   

• ITU also develops and updates guidance on the use of radio-frequency spectrum and protection of radio astronomical stations from harmful interference - the Handbook on Radio Astronomy (see short description below)

Important decisions taken by WRCs in the last decade, such as the extension of frequency allocations to the radio astronomy service between 71 GHz and 275 GHz and recognition of space-based radio astronomy (as well as others), allow to improve the precision of radio astronomical observations.