This photograph of Saturn, taken on its equinox, was taken up close by the robotic spacecraft Cassini. Photographs taken during the planet's equinox, the point in orbit in which the sun's disk is exactly overhead at the planet's equator, show the shadow of the rings as a thin band dividing the planet in two. NASA/JPL/Space Science Institute
New insights into the nature of Saturn's rings are revealed in this panoramic mosaic of 15 images taken during the planet's August 2009 equinox. The illumination geometry that accompanies equinox lowers the sun's angle to the ring plane, significantly darkens the rings, and causes out-of-plane structures to cast long shadows across the rings. Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons, but also the shadows of newly revealed vertical structures in the rings themselves. NASA/JPL/Space Science Institute
Alternating light and dark bands, extending a great distance across Saturn's D and C rings, are shown here in these Cassini images taken one month before the planet's August 2009 equinox. The periodic brightness variations in the rings are almost certainly caused by the changing slopes in the rippled ring plane, much like the corrugations of a tin roof. Although previous Cassini observations had revealed corrugations in the D ring extending over 500 miles, this image shows these features extending for 6,200 miles into the C ring. NASA/JPL/Space Science Institute
Near the middle of the image, shadows are cast by vertically extended clumps in the kinky, discontinuous ringlets of the Encke Gap in the A ring. These clumps are casting shadows approximately 170 miles long, implying a clump height about 2,000 feet above the ring plane. NASA/JPL/Space Science Institute
This photo from the Cassini spacecraft looks down on the north pole of Saturn's moon Dione and the fine fractures that cross its trailing hemisphere. NASA/JPL/Space Science Institute
This undated true color image by the Cassini spacecraft released by NASA shows Saturn's largest moon, Titan, passing in front of the planet and its rings. A study released June, 2012 suggests there may be an ocean below Titan's frigid surface. NASA/AP
Saturn's moon Dione is shown against the globe of Saturn as Cassini approached the icy moon for its close rendezvous, 2004. The images used to create this view were obtained with the Cassini spacecraft wide-angle camera at a distance of approximately 603,000 kilometers (375,000 miles) from Dione. NASA/JPL/Space Science Institute/AP
Recent Cassini images of Saturn's moon Enceladus backlit by the sun show the fountain-like sources of the fine spray of material that towers over the south polar region. The image was taken looking more or less broadside at the "tiger stripe" fractures observed in earlier Enceladus images. It shows discrete plumes of a variety of apparent sizes above the limb of the moon. The greatly enhanced and colorized image shows the enormous extent of the fainter, larger-scale component of the plume. NASA-JPL
An artists' rendition of the Cassini spacecraft shows it approaching the planet Saturn and its magnificent rings. The glint of light behind the magnetometer boom at the bottom of the spacecraft represents the reflection of the sun. Since Saturn is 930 million miles away from the sun, and consequently, about 746 million miles away from Earth, from this perspective one can get a sense in the image just how far the Cassini spacecraft has to travel to reach the mysterious ringed planet. NASA
Why do the dunes on Titan, Saturn's largest moon, look as though they were formed by winds blowing opposite to the moon's prevailing winds? Using a decades-old wind tunnel, scientists may finally have an answer.
Sen—Scientists have used a wind tunnel to study the dunes on Saturn's largest moon, to find out what they are made of and why they appear to be formed in a direction opposite to that of Titan's prevailing winds.