The
International Year of Astronomy (
IYA2009) was a year-long celebration of
astronomy that took 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), was also endorsed by
UNESCO, the UN body responsible for educational, scientific, and cultural matters.