100 Hours of Astronomy - Astronomy Pictures of the Day

The International Year of Astronomy 2009 Cornerstone Project, "100 Hours of Astronomy," is on track to be the largest single science public outreach event ever. More than 1500 events have been registered in over 130 countries and this number is increasing every day. 100 Hours of Astronomy is a truly global project; an event on a scale never attempted before, with more than one million people expected to participate!

This gallery features images from NASA's "Astronomy Picture of the Day."