It’s no secret that Saturn has some pretty peculiar moons floating around it. For instance, Saturn’s innermost moon, Pan, looks a lot like a walnut. Another one of Saturn’s small moons, Atlas, resembles a flying saucer. Both Pan and Atlas have been described as space ravioli, as previously reported by the Inquisitr. Meanwhile, Saturn’s moon Prometheus is often compared to a cigar due to its elongated shape — and even to a whale.
The gas giant has 62 confirmed moons and an additional nine that are waiting to be named, according to Cool Cosmos. And, while many of them sport bizarre shapes that boggle the mind, none are as artistic as this newly emerged photo of Dione and Rhea.
Captured by the late Cassini spacecraft on July 27, 2010, the dazzling snapshot showcases the two Saturnian moons in a very festive display that spreads the holiday cheer. The photo shows the icy moons Dione and Rhea stacked one above the other in the shape of an elegant “space snowman,” as noticed by the European Space Agency (ESA).
“This very convincing image of a conjoined moon masquerading as a snowman is actually two separate Saturnian moons — Dione and Rhea — taken from such an angle by the international Cassini spacecraft that they appear as one,” ESA officials said in a statement.
This space 'snowman' ⛄️ is actually two separate moons of #Saturn – Dione and Rhea – which appear as one in this unusual view by the international #Cassini mission.— ESA (@esa) December 10, 2018
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Unveiled by the space agency on December 10, this dazzling Cassini snapshot is the product of an optical illusion, as the ESA explained in the photo release.
While Dione and Rhea seem perfectly in sync as they cozy up to form a snowman in space, this is nothing but a trick of perspective. In reality, the two Saturnian moons sit a few hundred thousand miles apart and only appear to have come together for this rare Cassini shot due to the angle at which the spacecraft’s camera was pointed.
Pictured as the head of the snowman, Dione “was actually closer to the spacecraft at the time the image was taken,” notes the ESA. While Dione was photographed from a distance of around 685,000 miles, Rhea was sitting further away from Cassini, floating some about 995,000 miles away from the NASA-ESA probe.
“Dione has a diameter of 1,123 kilometers [698 miles] and Rhea is larger, with a diameter of 1,528 kilometers [949 miles], but they appear to have a similar size in this image due to the difference in distance,” underlined the ESA.
This apparent symmetry contributes to the snowman mirage, which is enhanced by the fact that the two moons have similarly reflective surfaces, creating the impression that we’re looking at a single object.
Another detail that makes the moons appear “to blend seamlessly together” in this newly released Cassini photo is the fact that Dione has a large crater located at its south pole. Known as Evander, the crater creates the illusion that the two moons are perfectly conjoined.
The differences between Dione and Rhea go beyond their size discrepancy. Dione’s composition is one-third rock, the moon’s core included, and two-thirds ice. At the same time, Rhea — Saturn’s second largest moon, after the behemoth Titan — is made up of around one-quarter rock and three-quarters ice. This essentially makes it “a giant frozen dirty snowball,” the ESA points out.
In addition, the two moons sit at different distances from their parent planet, the gas giant Saturn.
“Dione lies at roughly the same distance as the moon from the Earth and orbits around the ringed planet in just 2.7 days, while Rhea sits slightly further away and has a 4.5-day orbit.”
Last but not least, Dione is severely pockmarked by craters. While it’s not unusual for a moon to be pummeled by space debris — take a look at Earth’s moon, for example — the craters on Dione seem to be on the wrong side of the moon. In a strange twist of events, Dione has many more craters on its trailing hemisphere, which is the side facing away from its motion through space, than on its leading hemisphere, notes Space.
“This unusual cratering pattern suggests that it suffered an impact which spun the moon around 180 degrees,” explained ESA officials.