Shadows and Rings
Among the interplay of Saturn’s shadow and rings, Mimas, which appears in the lower-right corner of the image, orbits Saturn as a set of the ever-intriguing spokes appear in the B ring (just to the right of center).
Scientists expect that spokes will soon cease to form as Saturn approaches northern equinox. The exact mechanism of spoke formation is still the subject of debate, but ring scientists do know that spokes no longer appear when the Sun is higher in Saturn’s sky. It is believed that this has to do with the ability of micron-sized ring grains to maintain an electrical charge and levitate above the rings, forming spokes. Thus, these may be some of the last spokes ever imaged by Cassini.
This view looks toward the unilluminated side of the rings from about 38 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Oct. 22, 2013.
The view was obtained at a distance of approximately 1.6 million miles (2.6 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 146 degrees. Image scale is 93 miles (150 kilometers) per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.
Image Credit: NASA/JPL-Caltech/Space Science Institute
Estonian astrophotographer Raivo Hein really brings out the beauty of the world we live in.
I met with the man behind these amazing images today as he gave a brief lecture about taking and processing the photographs. Shortly, one image takes several days and over 10 programs to complete. He takes the images from his own little observatory, which he runs from another city.
Millions of Stars in Omega Centauri
Featured in the sharp telescopic image, globular star cluster Omega Centauri (NGC 5139) is some 15,000 light-years away and 150 light-years in diameter. Packed with about 10 million stars much older than the Sun, Omega Cen is the largest of 200 or so known globular clusters that roam the halo of our Milky Way galaxy. Though most star clusters consist of stars with the same age and composition, the enigmatic Omega Cen exhibits the presence of different stellar populations with a spread of ages and chemical abundances. In fact, Omega Cen may be the remnant core of a small galaxy merging with the Milky Way.