Waiting it out
23:30 at home in Montevideo. It is June 30 and I know out there in the lonely splendor slightly above the ring plane, Cassini must be turning on its engine. No way to know what is really going on so I disconnect from Internet, turn off the computer and go to bed. Which was the outcome was to be known only in the morning hours of July 1. Cassini had to turn around well in advance of its plunge into the ring plane, between the outer F and G rings. It had to be turned with the big dish antenna pointing forward to fend off likely impacts with micrometeorites exposing its less vulnerable side. After crossing it should turn again pointing the engine nozzle forward to begin the braking burn. Only after the burn should it turn the antenna again towards Earth and signal home, an then it should take over one and a half hour for the news to arrive flying at the speed of light.
Incredibly enough, everything went as planned. No unexpected yet feared boulder shattered the ship, no engine failure, no software glitch. Telemetry signaling the turn on and turn off arrived at the deep space tracking network spawning cheers from the anxiously waiting ground teams. An it did take some pictures for sure, the closest to be gathered of the ring system in the whole campaign.
Unexpected, as expected
Remember Carolyn Porco? She managed to send Eugene Shoemaker's ashes to the Moon, and is imaging team leader for Cassini. After looking at the first ever close-ups, could only comment in disbelief they looked fake, but of course are real. They also bring interesting insights. Look at the ripples bordering the chasm known as the Encke division. Certainly one could well take them as stream ripples on a sandy beach, don't you think so? Yet there is no stream there, and the material is an extremely thin (tens to hundreds of meters thick) layer of loose ice boulders, only meters to tens of meters in size. The physical laws governing their movement are basically Newton's gravitational mechanics. A stately dance where gentle tugs from Saturn, the larger moons, tiny moonlets and companion chunks of varied sizes mutually interact spawning orderly moving patterns. Other physical systems ranging from waves in a pond, masses and springs, pressure (acoustic) waves, heat distribution, and current flowing through electronic circuits, stand from very different physical interactions, yet have in common a mathematical description - expressed as what is known as linear differential equations - that result in patterns that repeat in each realm.
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