Saturn has been known of since ancient times. Saturn is the second largest planet in our solar system and the sixth planet from the sun. Saturn has an equatorial radius of 60,268km and a polar radius of 54,364 km. Saturn is wider around the equator because of its fast orbital speed, completing one orbit in 10.656 hours. The high orbital speed causes the planet to form the shape known as an oblate spheroid. The high orbital speed is also evident in the appearance of bands in the atmosphere of the planet. The multiple bands are the result of the Coriolis effect, which occurs on planets with a high orbital speed. Saturn is the only planet with a density less than that of water. With a mean density of 0.687g/cm³, Saturn is the least dense planet in our solar system and would theoretically float in water. Saturn is known for its rings, which were first observerd by Galileo in 1610 and are one of the most spectacular wonders of the solar system. These rings, which are made up of pieces of ice, span of height of around ten meters. The rings are so thin, that they seem invisible when viewed straight on horizontally. Despite the thin nature of the rings, they are opaque and cast a shadow onto Saturn.
The picturue on the upper left shows Saturn through the red, green, and blue filters and the upper-right picture shows Saturn through the infrared, red, and green filters. The upper-left picture displays saturn as it is seen to the human eye. The white rings appear white, as they are composed almost entirely of water ice. While Saturn's atmosphere is composed of about 96% hydrogen, the presence of other gases can be determined by using alternative wavelengths to view the planet. In the pictures above, we are viewing the northern hemisphere of the planet. This view of the planet shows the top of the rings and allows us to see the shadow of the planet on the rings on the right side of the planet. Ten years ago, a viewer of Saturn from Earth would have seen the southern hemisphere of Saturn. Images of this are available here. The images above show that the sun is not shining on Saturn from the direction we view Saturn from, but rather from the left of our view.
The lower picture shows five of Saturn's moons, from left to right: Enceladus, Titan, Tethys, Dione, and Rhea. This linked graphic from JPL labels which moon is which. The moon Hyperion was also faintly visible in the images but was cropped out. Hyperion appeared to the southeast of Saturn.
"Saturn." Natinoal Maritime Museum, 4 Jan. 2005. 22 Apr. 2011. <http://www.nmm.ac.uk/explore/astronomy-and-time/astronomy-facts/solar-system/saturn>.
"Saturn." Universe Guide. 22 Apr. 2011. <http://www.universeguide.com/Saturn.php>.
Williams, Dr. David R. Saturn Fact Sheet. NASA, 17 Nov. 2010. Web. 22 Apr. 2011. <http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html>.
|Right Ascension (J2000)||12:58:03|
|Filters used||B (Blue), V (Green), R (Red), I (Infrared)|
|Exposure time per filter||B (1s), V (0.15s), R (0.13s), and I (0.2s)|
|Date observed||March 25, 2011, 09:30 UT|