“There has yet been no greater visual survey of a planetary system in the outer solar system than Cassini’s imaging of the bodies in the Saturn environment. The enchanting beauty and visual clarity of our images have earned the attention and admiration of people all over the world, and our scientific discoveries, some of them quite startling, have revolutionized our understanding of everything Saturnian.” – Cassini Imaging Central Laboratory for Operations (CICLOPS)
Like a circus barker luring people into the big tent, the ringed planet Saturn is center of attention these clear nights of late Summer 2017.
And Saturn is about to go viral on the Internet when NASA’s $3 billion Cassini spacecraft commits a hari-kari suicide plunge in the planet’s atmosphere, ending a fantastic 13-year mission.
After 293 orbits of Saturn from all angles—the last 26 in the gap between the gaseous planet and rings!—Cassini is ending an incredible mission. The fatal plunge is a standard maneuver for orbiting, planetary spacecraft to prohibit any possible contamination of any moons with Earth germs should it crash there.
You can see Saturn with your own eyes high in the south between Scorpius and Sagittarius, in the constellation Ophiuchus. The yellow hue is a contrast to the red star Antares to the right in Scorpius.
Binoculars don’t have enough power, but a telescope at even low power will show the rings as “handles” on each side of the yellowish globe—at least that’s what Galileo said when he saw Saturn in his primitive telescope in 1610.
If you have haven’t seen Saturn in a telescope, you will never forget your first time. Jaws usually drop. Youngsters shriek. Some adults even question that the telescope is pointed at a photograph of the sixth planet.
Indeed, Saturn is one of the few celestial objects that look like the astrophotos. There is nothing through a telescope quite like Saturn. That’s why amateur astronomers, like myself, never tire of seeing this ringed world at every opportunity.
Saturn is the symbol of astronomy.
And there is certainly more to Saturn that meets the eye. Like the catalog of images from Cassini, all on their Ciclops.org website. Many are astonishing works of art as the rings, moons and planet are captured in various juxtapositions.
The Cassini spacecraft is named after the late 17th Century Italian astronomer Giovanni Cassini, who first pointed a telescope powerful enough to see the black division in the rings that bears his name.
The Cassini division is easily seen in most backyard telescopes at around 150-power. Also seen in a telescope are several of Saturn’s moons, including the bright, star-like Titan, the largest moon in the solar system.
Saturn is the second largest planet in the solar system at 74,900 miles in diameter. It is rapidly spinning around once in less than 11 hours, flattening the poles, giving Saturn a noticeable squashed look in a telescope.
Like giant Jupiter (88,000 miles), and smaller Uranus and Neptune (each about 32,000 miles), Saturn is enshrouded in super-cool gases like nitrogen, methane and ammonia. Their cores are a mystery—maybe solid metals, but most likely liquid metallic hydrogen that creates a wicked electromagnetic system around these gas giants.
Despite being so huge, Saturn has a density less than that of liquid water. One of the first facts a youngster learns in school about Saturn is the planet would float on water!
The rings of Saturn are incredibly thin. They are 170,000 miles from tip to tip, but less than 10 miles thick. That is the thickness of a quarter, stretched 10 miles across!
Looking like the grooves of an old, vinyl phonograph record, the rings are thousands of ringlets composed of billions of ice and rock chunks ranging in size from boulders to gravel to sand. Dust is raised in changing radial patterns above and below certain portions of the rings.
Saturn has about 63 moons, only 13 of which are larger than 30 miles in diameter. A key factor to the glorious rings may be dozens of small moons that are gravitational shepherds of the system of rubble.
Up to five of Saturn’s moons are seen in a backyard telescope. And they change position night after night. Looking at Saturn is never tiresome, as the subtle cloud features on the planet also change throughout the night.
If a stargaze is planned when Saturn is in the sky, don’t miss it! And watch the final hours of Cassini as it plunges into the Saturn atmosphere on Sept. 15, live on the Cassini websites and Facebook and other astronomy sources on the world-wide web.