Saturn has been observed by astronomers and studied by spacecraft. Plus, the planet looks beautiful this month.
Transcript:What's Up for March? Saturn, the jewel of the solar system
Hello and welcome. I'm Jane Houston Jones from NASA's Jet Propulsion Laboratory in Pasadena, California.
During 2009, we're celebrating International Year of Astronomy by taking you on a tour of one of the month's best celestial objects. And this month, it's Saturn!
When Galileo aimed his telescopes at Saturn in 1610 he wasn't sure what he was seeing. He thought the rings were "handles" or large moons on either side of the planet.
A few years later in 1612, he was astounded that the "handles" he previously observed had disappeared! And in 1616, the handles were back, but they looked different. This time he saw two half-circles on either side of the round globe of Saturn.
Other observers added to the knowledge of the Saturn system in the 1600's. Christian Huygens observed that every 14 to 15 years, Earth passes through the plane of Saturn's rings, and they appear to disappear. This is the same view that Galileo saw half a century earlier.
Giovanni Cassini discovered new moons of Saturn during the ring plane crossings of 1671 and again in 1684. He was the first to see a gap in the rings, which was later named the Cassini Divison in his honor.
Three hundred years later, our fascination with the Saturn system grew with the flybys of Voyager 1 and 2. Voyager discovered a new outer ring called the G-ring, spokes in the B-ring and braiding on the F ring. The F ring had just been discovered the year before by the Pioneer 11 spacecraft. New moons, ringlets and gaps between Saturn's rings were just some of the Voyagers' many discoveries.
The Cassini spacecraft has been returning amazing results from the Saturn System for almost 5 years. It's in the middle of a 2-year extended mission right now. One of the mission highlights was the landing of the Huygens Probe on Saturn's moon Titan.
Geysers spewing water ice through vents on the moon Enceladus remind us of the Old Faithful Geyser on Earth.
This summer, for the first time ever, telescopes on earth and a spacecraft at Saturn will both view Saturn's rings as they seem to disappear. Cassini will have a bird's-eye view of this event.
This month, don't miss Venus in the western sky right at sunset, while you wait a few hours for Saturn to rise in the East. Saturn will be worth the wait. It always looks more impressive when it's higher in the sky.
You can read more about Saturn this month on NASA's International Year of Astronomy website: astronomy2009.nasa.gov
And you can learn all about NASA's missions at www.nasa.gov
That's all for this month. I'm Jane Houston Jones.