In a just released image from NASA, the Hubble Telescope captured a rare alignment of Jupiter's three largest moons. Ganymede, Callisto and Io simultaneously passed between Jupiter and the sun and cast shadows onto the planet. In addition to the shadows, two of the moons can also be seen in the photo. For more details, view(1) this article from New Scientist.

1. http://www.newscientist.com/news/news.jsp?id=ns99996624