This picture comes to Earth from the Cassini spacecraft. From the left, five moons of Saturn are visible: Janus, Pandora, Enceladus, Mimas, and Rhea (bisected by the edge of the image). The photograph was taken at a distance of 684,000 miles from Rhea.
We want to hear what you think about this article. Submit a letter to the editor or write to firstname.lastname@example.org.
Rebecca J. Rosen is a senior editor at The Atlantic, where she oversees the Family and Education sections.