2009 (MMIX) was a common year starting on Thursday of the Gregorian calendar, the 2009th year of the Common Era (CE) and Anno Domini(AD) designations, the 9th year of the 3rd millennium and the 21st century, and the 10th and last year of the 2000sdecade.
2009 was designated as the International Year of Astronomy by the United Nations to coincide with the 400th anniversary of Galileo Galilei's first known astronomical studies with a telescope and the publication of Astronomia Nova by Johannes Kepler. It was also declared as the International Year of Natural Fibres by the United Nations General Assembly, as well as the International Year of Reconciliation and the Year of the Gorilla (UNEP and UNESCO).