Astronomy Picture of the Day . ... However, this intriguing picture was made to take advantage of an unusual orientation, with the Sun actually illuminating the rings from below. ... In our neck of the Galaxy stars are too far apart to be in danger of colliding, but in the dense cores of globular star clusters star collisions may be relatively common. ... Ganymede: The Largest Moon in the Solar System . ... The Last Moon Shot . ... Welcome to the sixth year of Astronomy Picture of the Day (APOD)! ...