Skylight: Saturn Shows Off Its Rings

Saturn Shows Off Its Rings - Transcript [A view of the night sky is slowly rotating. A pink circle appears around Saturn.] Saturn adorns in the southwest sky this season, [Outline of constellation Ophiuchus appears: a man holding a serpent.] ... in the constellation Ophiuchus. [View of Saturn, very small, with rings barely perceivable.] Through binoculars, it appears lemon-shaped, suggesting the presence of rings. [Saturn appears a little larger, with rings apparent on either side and a few of its moons visible.] A telescope reveals a ringed jewel set among its moons. As Saturn orbits the sun, we observe its rings at varying angles. [A close-up of Saturn, spinning on its axis with time sped up. Timer at top of view indicates the year is 1981, changing by one year every second. As the years progress, Saturn's tilt relative to the observer changes, showing a different view of the rings.] The rings are fully tilted toward us during Saturn's northern summer solstice. [Time pauses at 1987. The north hemisphere of Saturn is tilted directly toward observer, showing the best view of north side of the rings. Time resumes, our view of the rings narrows as the tilt continues to shift.] Around Saturn's equinoxes, its rings nearly disappear. [Time pauses at 1995. The rings are invisible against the background sky, and appear as a thin, dark line on the planet. Time resumes, the tilt of rings progresses to tilt fully away in 2003, edge on again in 2009, and back to tilt fully towards observer in 2017. Time pauses in 2017.] This month we see the rings at their maximum tilt as they appeared in 1987, one Saturnian year ago. [Saturn and the year label fade, leaving a star field in view. We look to the right.] Pioneer 11 first visited Saturn in 1979, followed by the Voyager probes in 1980 and 1981. [Continues to pan right. Cassini probe appears as a distant speck which quickly approaches the camera, resolving in shape and we see some details on the probe.] In 2004, the Cassini probe reached Saturn, and over the next 13 years enriched our understanding of the planet. [Following the Cassini probe as it approaches Saturn, Saturn coming into view from right.] Through the eyes of Cassini we saw beyond visible light, illuminating the exquisite detail of Saturn's rings, [Date is now 2005. Cassini continues around Saturn, which fills the background. A picture from the Cassini mission blends into view showing the rings, and fills the view as Cassini and Saturn fade down. The image shows details of the rings in false color. All Cassini image credits: NASA/JPL-Caltech/Space Sciences Institute It's now 2008. We see Saturn from above its south pole. The view swings past Saturn and zooms in toward the moon Enceladus, showing its striped features.] ...its menagerie of moons, [Enceladus fades to Cassini image of the stripes on Enceladus's surface. Over Saturn's north pole, it's now 2011. We swing toward Saturn's equator, seeing its rings edge-on.] ...storms and unexpected cloud patterns. [Saturn fades to Cassini image of the same view, with a storm streaking across Saturn's mid northern latitudes. Date 2013. Over Saturn's north pole. We're now looking toward the dark side of Saturn, unlit by sun, to see back-lit rings and eclipsed sun.] Cassini also reminded us that amid the vast cosmic ocean, [Saturn fades to Cassini image of iconic back-lit view of planet and rings.] Earth is merely a pale, blue dot. An arrow points to a tiny spec in the image just below Saturn's rings... Earth captured by Cassini's camera. [Fade to black, credits begin to roll. Music fades.]