A True 'Ring Moon'
February 22, 2008
Janus skirts the edges of Saturn's main rings. The Cassini spacecraft has shown that this small moon and its co-orbital companion, Epimetheus, also share their orbit with a diffuse ring of fine particles.
See The Janus/Epimetheus Ring for more information about the Janus-Epimetheus ring.
This view looks toward the unilluminated side of the rings from about 11 degrees above the ringplane. Above Janus (181 kilometers, or 113 miles across), at upper left, are the narrow F ring and the outer part of the A ring.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 19, 2008. The view was acquired at a distance of approximately 1.5 million kilometers (940,000 miles) from Janus and at a Sun-Janus-spacecraft, or phase, angle of 21 degrees. Image scale is 9 kilometers (6 miles) 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.
Credit: NASA/JPL/Space Science Institute