Saturn's starring role
Posted: Tuesday, March 20, 2007 6:12 PM by Alan Boyle
NASA / ESA / Univ. of Ariz. |
These images from the Hubble Space Telescope, showing Titan and its shadow
passing over Saturn's disk, were taken in 1995 and processed to produce a movie.
Click on the image to watch three videos narrated by MSNBC's Alan Boyle.
|
The Hubble Space Telescope isn’t exactly a movie camera - but just add a little special-effects software, and you can turn Hubble’s still images of Saturn into some pretty cool mini-documentaries. Three movie clips released today show Saturnian moons zipping around the ringed planet in scenes that rival the chariot race from “Ben-Hur.”
We see two sides of Saturn in this trilogy: The first couple of clips date back to 1995, when the planet's rings were last seen edge-on from Earth. These views highlight the racetrack moons, starting out with Titan (and its shadow) passing over the planet's pastel-colored disk. Another moon, Tethys, appears as a white speck on the backstretch. The second clip shows Enceladus neck-and-neck with Dione and Mimas, passing in front of Saturn, with Tethys passing behind.
The third clip fast-forwards to 2003, when the rings were at their maximum tilt as seen from Earth. This perspective gave astronomers their best view of Saturn's southern hemisphere, with banded cloud patterns spinning around the globe at a rate of one revolution every 10 hours. Centralized storms show up as blue and white dots on the disk.
Because Saturn orbits the sun every 30 years, these extreme edge-on and ring-tilted perspectives are visible only every 15 years. In each case, Hubble snapped only about a dozen time-lapse photos of the planet and its moons, over periods ranging from 10 hours (for the edge-on views) to 24 hours (for the ring-tilted view).
As explained in today's image advisory, the telescope's science team fed those images into a computer program that filled in the missing frames to produce the smooth-running, sped-up movies.
Any good movie should leave you hungry for more - and fortunately, Saturn has a rich filmography. For example, there's "The Perfect Storm," a time-lapse view of a hurricane at the planet's south pole. More recently, the Cassini imaging team put together a highlights reel that includes short clips as well as "feature films." One of the classics, titled "The Great Crossing," was released just this month.
If it's photos you're looking for, we have a few slide shows that should fill the bill, including the greatest hits from Hubble, Saturn and the Cassini orbiter. And for the latest on Hubble and Saturn, you should keep tabs on HubbleSite for the former, and NASA's Saturn home page for the latter.
