Tag Archives: Rings of Saturn

Astronomy Picture of the Day – In the Shadow of Saturn’s Rings

Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2012 July 3

In the Shadow of Saturn’s Rings 

 Image Credit: NASA/JPL-Caltech/Space Science Institute/J. Major

 Explanation: Humanity’s  robot orbiting Saturn has recorded yet another amazing view. That robot, of course, is the  spacecraft Cassini, while the new amazing view includes a  bright moon,  thin rings,  oddly broken clouds, and  warped shadows. Titan, Saturn’s largest moon, appears above as a featureless tan as it is continually shrouded in thick clouds. The rings of Saturn are seen as a thin line because they are so flat and imaged nearly edge on. Details of Saturn’s rings are therefore best visible in the  dark ring shadows seen across the giant planet’s cloud tops. Since the ring  particles orbit in the same plane as Titan, they appear to skewer the foreground moon. In the upper hemisphere of Saturn, the clouds show many details, including  dips in long bright bands  indicating disturbances in a high altitude jet stream. Recent precise measurements of how much Titan  flexes as it orbits Saturn hint that  vast oceans of water might exist deep underground.

Astronomy Picture of the Day for Jan. 5

Astronomy Picture of the Day

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2012 January 5
See Explanation.  Clicking on the picture will download the highest resolution version available.

Ringside with Titan and Dione
Credit : Cassini Imaging Team, SSI, JPL, ESA, NASA  


Explanation: Orbiting in the plane of Saturn’s rings, Saturnian moons have a perpetual ringside view of the gorgeous gas giant planet. Of course, while passing near the ring plane the Cassini spacecraft also shares their stunning perspective. The rings themselves can be seen slicing across the middle of this Cassini snapshot from May of last year. The scene features Titan, largest, and Dione, third largest moon of Saturn. Remarkably thin, the bright rings still cast arcing shadows across the planet’s cloud tops at the bottom of the frame. Pale Dione is about 1,100 kilometers across and orbits over 300,000 kilometers from the visible outer edge of the A ring. Dione is seen through Titan’s atmospheric haze. At 5,150 kilometers across, Titan is about 2.3 million kilometers from Cassini, while Dione is 3.2 million kilometers away.

NASA Image of the Day for October 1st

Saturn’s Silhouetted Clouds

This false-color mosaic shows deep-level clouds silhouetted against Saturn’s glowing interior. This mosaic shows the entire planet, including features like Saturn’s ring shadows and the terminator, the boundary between day and night.

The blue-green color (lower right) is sunlight scattered off clouds high in Saturn’s atmosphere and the red color (upper left) is the glow of thermal radiation from Saturn’s warm interior, easily seen on Saturn’s night side (top left), within the shadow of the rings, and with somewhat less contrast on Saturn’s day side (bottom right). The darker areas within Saturn show the strongest thermal radiation. The bright red color indicates areas where Saturn’s atmosphere is relatively clear. The great variety of cloud shapes and sizes reveals a surprisingly active planet below the overlying sun-scattering haze.

The brighter glow of the northern hemisphere versus the southern indicates that the clouds and hazes there are noticeably thinner than those in the south. Scientists speculate that this is a seasonal effect, and if so, it will change as the northern hemisphere enters springtime during the next few years.

The data were obtained in February 2006 at a distance of 1.6 million kilometers (1 million miles) from directly over the plane of Saturn’s rings, which appear here as a thin, blue line over the equator.

Image credit: NASA/JPL/University of Arizona

Astronomy Picture of the Day for Sept. 4th

 Astronomy Picture of the Day 

Discover the cosmos!Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

 2011 September 4

 In the Shadow of Saturn
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Explanation: In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn drifted in giant planet’s shadow for about 12 hours in 2006 and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn’s rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn’s E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth.