The big news in the sky this week is all about Cassini, the spacecraft that will plunge into Saturn on Friday, after 20 years of fascinating voyage and discovery.
The Cassini spacecraft was named for Giovanni Domenico Cassini, the 17th century Italian astronomer who discovered four of Saturn’s moons and the division of Saturn’s rings, all at a time when the concept of the Earth orbiting the Sun was still stirring up trouble.
Cassini the spacecraft was dreamed up when Ronald Reagan was president, and launched in 1997, during the tenure of Bill Clinton. It arrived at Saturn in the first term of George W. Bush, in 2004, the same year Facebook went live online.
Cassini will plunge toward Saturn on Friday morning, after dawn for us, so by the time we see Saturn in the evening sky, the “death dive” will have occurred. But bear in mind that Saturn is a gaseous planet, so there’s no real surface for Cassini to crash into. In the last moments, it will go into a tumble, lose contact with Earth, and then, like a star falling through the Saturnian sky, it will burn up as it plunges through the atmosphere there.
To honor the end of Cassini’s era and its revelation of new mysteries, here is the poetry John Keats, which describes the deep sadness that was unleashed when the rebel Olympians overtook the Titan gods, of which Saturn was one.
Deep in the shady sadness of a vale
Far sunken from the healthy breath of morn,
Far from the fiery noon, and eve's one star,
Sat gray-hair'd Saturn, quiet as a stone,
Still as the silence round about his lair;
Forest on forest hung about his head
Like cloud on cloud. No stir of air was there,
Not so much life as on a summer's day
Robs not one light seed from the feather'd grass,