About:

1. It is celebrated twice a year, once on September 26 and other on May 2. 
2. It was coordinated by the International Astronomical Union (IAU).
3. The IAU was founded in 1919. 
4. India is a member of the Union. 
5. The headquarters of the Union is located in France.
6. The International Year of Astronomy was celebrated in 2009.
7. It was marked on 2009 to celebrate the 400th anniversary of observations of Galileo and also Kepler’s findings in 17th century.
8. In 1609, Galileo for the first time found craters and mountains on the moon that changes the perception of space.