"The International Year of Astronomy will be launched at UNESCO on 15 and 16 January. This United Nations year is a worldwide celebration of astronomy, with activities in almost 140 countries. One such activity, 100 hours of astronomy for example, will bring together as many amateur astronomers as possible from around the planet from 2 – 5 April.
The Year coincides with the 400th anniversary of Galileo’s first observations with an astronomical telescope. It is an opportunity for people all over the world to rediscover their place in the universe by observing the sky at night and during the day. It is also intended to provide a platform for informing the public about recent discoveries in astronomy, while demonstrating the central role that astronomy can play in science education."
As written at Astronomy2009.org:
The International Year of Astronomy 2009 is a global effort initiated by the International Astronomical Union and UNESCO to help the citizens of the world rediscover their place in the Universe through the day- and night-time sky, and thereby engage a personal sense of wonder and discovery.
Everyone should realise the impact of astronomy and other fundamental sciences on our daily lives, and understand how scientific knowledge can contribute to a more equitable and peaceful society. IYA2009 activities will take place locally, nationally, regionally and internationally. National Nodes have been formed in each country to prepare activities for 2009. These nodes will establish collaborations between professional and amateur astronomers, science centres and science communicators to prepare activities for 2009. Already now, 136 countries are involved and well over 140 are expected to participate eventually.
To help coordinate this huge global programme and to provide an important resource for the participating countries, the IAU has established a central Secretariat and an IYA2009 website (www.astronomy2009.org) as the principal IYA2009 resource for public, professionals and media alike."
"On January 20th, the IYA 2009 in Germany will be festively inaugurated by Dr. Anette Schavan, federal minister for education and research."
What follows is the official - fantastic - video trailer for the IYA: