Among all the moons of Saturn, Pan is standing out for some rather curious reasons. Based on new images from NASA’s Cassini mission, the diminutive moon has alternately been described as resembling a walnut, ravioli, a “space empanada,” and in a rare non-edible example, a “cosmic turtle shell.” In other words, it’s a rather “delicious” moon due to how it resembles multiple types of food.
Although it might sound like a completely new discovery, the fact that Saturn’s moon Pan has a peculiar shape is nothing new to astronomers. But as Geekwire related, the new photos from NASA are the clearest proof so far of this unusual shape.
University of California-Berkeley researcher and Cassini imaging team leader Carolyn C. Porco told the New York Times that she first thought the photos from the orbiter were an artist’s rendering of Saturn’s moon Pan. But she soon realized that the images were for real, and the clearest her team has seen to date.
“The detailing in the last images is just astounding,” said Porco. “You can see where this ridge actually curves like a ribbon and where it’s not completely smooth.”
On Tuesday, the Cassini orbiter got its best look so far at Pan, coming just 15,000-plus miles within the tiny (20-mile-wide) satellite. And on Thursday, NASA released close-up photos of the moon, which appears like a “flattened flying saucer, complete with a bulging ridge around the edge.” This sparked conversation on social media, as many compared Pan to a number of foods – most commonly, the moon has been described as looking as ravioli or like a walnut, though Science was a bit more unique in its description, referring to Pan as a “pan-fried dumpling or an empanada.”
In its official press release describing this unusual moon of Saturn, NASA says Pan is the ringed planet’s innermost known moon, having been discovered by astronomer Mark Showalter in 1990 after analyzing images taken by the Voyager 2 spacecraft nine years prior. It orbits about 83,000 miles away from Saturn, and is located within the Encke Gap of the planet’s A-ring, with a mean radius of about 8.8 miles. Pan orbits its host planet every 13.8 hours, making it one of its shepherd moons, and the one most instrumental in ensuring the 200-mile Encke Gap remains open.
In another interesting note, NASA wrote that Pan creates “wakes,” which are stripes on both sides of Saturn’s ring material, and also adds to the gravity of its ring particles.
“Since ring particles closer to Saturn than Pan move faster in their orbits, these particles pass the moon and receive a gravitational ‘kick’ from Pan as they do. This kick causes waves to develop in the gap and also throughout the ring, extending hundreds of miles into the rings. These waves intersect downstream to create the wakes, places where ring material has bunched up in an orderly manner thanks to Pan’s gravitational kick.”
— Cosmical (@CosmicalComic) March 10, 2017
Still, one has to wonder why Pan resembles so many kinds of food, rather than your typical celestial being. NPR cited a study from 2007 where researchers noted the moon’s equatorial ridges and wrote that these may have come about from the buildup of the aforementioned ring particles that accumulated over a long period of time and millions of orbits. These ridges are also a distinctive feature of another one of Saturn’s moons, Atlas.
“We propose that Pan and Atlas ridges are kilometers-thick ‘ring-particle piles’ formed after the satellites themselves and after the flattening of the rings but before the complete depletion of ring material from their surroundings.”
According to NASA, Saturn’s moons originally got their names from the Titans of Greco-Roman mythology and their descendants. Over time, the space agency had to draw inspiration from other cultures’ mythologies as it kept discovering new moons orbiting Saturn. Pan, in specific, was named after the Greek god of nature and the forest.
[Featured Image by NASA/JPL-Caltech/Space Science Institute]