Two tiny moons of Saturn, almost lost amid the planet’s enormous rings, are seen orbiting in this Cassini probe image. Pan, visible within the Encke Gap near lower-right, is in the process of overtaking the slower Atlas, visible at upper-left.
Voyager 2 made its closest approach to Saturn 35 years ago — on 25 August 1981. What the Voyagers revealed at the planet was so phenomenal that, just one year later, a joint American and European working group began discussing a mission that would carry on Voyager’s legacy at Saturn.
In this image from NASA’s Cassini spacecraft, Saturn’s moon Dione reveals its past via contrasts. The features visible here are a mixture of tectonics — the bright, linear features — and impact cratering — the round features, which are spread across the entire surface.