Cassini image captures phantom rings
NASA's Cassini spacecraft has captured a stunning, and seemingly impossible view of Saturn's iconic ring system intersecting with a second set of phantom rings. The image was snapped using the probe's narrow-angle camera on Feb. 11, 2016.
Whilst a number of the planets that make up our solar system boast minor ring systems of their own, none can compare with the majesty of Saturn's adornment. Since arriving in Saturn's orbit in 2004, the Cassini has sent back a regular stream of images of the gas giant's rings, and has performed detailed analysis that has allowed us to unravel many secrets regarding the rings formation history, as well as its present-day characteristics.
For example, thanks to Cassini data, astronomers have observed that some of the gaps in Saturn's rings can be attributed to the formation of so called "shepherd moons." These satellite bodies formed from the ring material, and maintain the gaps with their continued presence.
In the image at the top of the page, the shepherd moon Pan was captured from a distance of 1.2 million miles (1.9 million km), appearing as a tiny spec of white in the center of the image, as it maintained a divide in Saturn's A ring.
The appearance of a second phantom ring is of course nothing more than an illusion. What you are actually seeing is the sunlight side of Saturn's ring system intersecting with its shadow, which is cast on the surface of the gas giant below. The planet's rings vary significantly in opacity from section to section, allowing the shadow to be easily observed through the delicate structures.
Such a scene can be seen in a wider context in the image above. Here, Saturn's rings and their distinctive shadow can be observed playing across the disk of the planet.