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Mostly Mute Monday: The Glory of Saturn’s Rings

“Saturn is remarkable in a number of ways; among all the planets we know of, it’s the least dense, and also the only one with a spectacularly visible set of rings. Composed of icy, dust-like material, these rings are not solid at all, but made up of particles that pass each other, stick together briefly and then fly apart once again.

Snowballs and planetesimals coalesce, only to be torn apart by tidal forces exerted by Saturn and its passing moons. Gaps in the inner rings are caused by the gravitational presence of moons themselves, while many of the outer rings — like Saturn’s E-ring, below — are actually caused by the moons themselves.”

From their discovery in the 1600s, Saturn’s rings have been a source of wonder and puzzlement to skywatchers everywhere. The only ring system visible through most telescopes from Earth, Saturn’s main rings at more than 70,000 km long, yet no more than 1 km in thickness. Once thought to have only two gaps in them, the Cassini spacecraft has revealed over a thousand, teaching us that Saturn’s rings are likely as old as the planet itself, and will likely continue to exist for as long as our Sun shines.

by Draw Bart Draw

This volcano in Indonesia emits electric-blue “lava” 

Kawah Ijen, in Indonesia’s Ijen volcano complex, is the biggest “acidic volcanic crater lake” in the world. It also happens to emit lava which appears luminescent and electric-blue. The lava, like all other lava, starts out red. Then it hits the “pockets.” (Photos via @reubenwu)

What’s Enceladus?

Before we tell you about Enceladus, let’s first talk about our Cassini spacecraft…

Our Cassini mission to Saturn is one of the most ambitious efforts in planetary space exploration ever mounted. Cassini is a sophisticated robotic spacecraft orbiting the ringed planet and studying the Saturnian system in detail.

Cassini completed its initial four-year mission to explore the Saturn System in June 2008. It has also completed its first mission extension in September 2010. Now, the health spacecraft is making exciting new discoveries in a second extension mission!

Enceladus

Enceladus is one of Saturn’s many moons, and is one of the brightest objects in our solar system. This moon is about as wide as Arizona, and displays at least five different types of terrain. The surface is believed to be geologically “young”, possibly less than 100 million years old.

Cassini first discovered continually-erupting fountains of icy material on Enceladus in 2005. Since then, the Saturn moon has become one of the most promising places in the solar system to search for present-day habitable environments.  

Scientists found that hydrothermal activity may be occurring on the seafloor of the moon’s underground ocean. In September, it was announced that its ocean –previously thought to only be a regional sea – was global!

Since Cassini is nearing the end of its mission, we are able to make a series of three close encounters with Enceladus, one of Saturn’s moons.

Close Encounters

On Oct. 14, Cassini performed a mid-range flyby of Enceladus, but the main event will take place on Oct. 28, when Cassini will come dizzyingly close to the icy moon. During this flyby, the spacecraft will pass a mere 30 miles above the moon’s south polar region!

This will be the deepest-ever dive through the moon’s plume of icy spray, where Cassini can collect images and valuable data about what’s going on beneath the frozen surface.

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The forward bulkhead and tunnel for Exploration Mission 1 undergoing paint priming, October 9, 2015. The EM-1 Orion capsule is being fabricated at the Michoud Assembly Facility in New Orleans, Louisiana. Seven major components are welded together to create the capsule’s pressure vessel. It then gets shipped to Kennedy Space Center in Florida where it undergoes final assembly and outfitting of key systems.

"He's not gone as long as we remember him."

mark your calendars!!!

launched eighteen years ago, the cassini orbiter is set to crash in to saturn next september, ending its mission to collect data, including these true colour images, on saturn and it’s moons and rings. saturn’s main rings, composed mostly of ice, are thought to have formed only a few hundred million years ago, long after the planet, and the solar system itself, were birthed some four and half billion years ago. 

though a hundred and seventy million miles in diameter, the main rings are only half a mile thick, with the brighter bands showing areas of greater density, and the darker, less dense areas swept relatively clear by the gravity of saturns’ moons - clear enough, anyways, for the cassini orbiter to pass through one of the gaps basically unscathed.

there is no consensus on how the rings were created, but a medium sized moon, either shattered by a meteor or pulled apart by the planet’s gravity, would account for the entire mass of the rings. there is, however, more of a consensus that in about fifty million years, saturn’s gravity will have pulled in the rings and swallowed them up. (but at least mars should have a ring by then.) 

saturn has over forty moons, including one found within a ring gap. these photos show the distant rhea and titan - the latter of which is larger than mercury and has its own atmosphere and hydrocarbon lake - and the inner most mimas and enceladus - the latter being notable for its encompassing liquid ocean of water and geothermal activity.  

Jupiter and Earth imaged together by NASA’s STEREO/HI-1A / via