10 March 2011
A Cassini spacecraft image of Saturn’s moon Dione
Credit: NASA/JPL/Space Science Institute
NASA recently published an interesting image of a bizarre Saturnian moon, known as Dione. The image was acquired by the Saturn-orbiting Cassini spacecraft, on 17 October 2010, when Cassini passed approximately 41,000 km from icy rugged Dione. The view is dominated by a large 120-km-wide crater at the center of the image.
Dione (1,123 km across) is one of the largest moons of Saturn. It is believed to be composed primarily of water ice, with a fraction of silicate rocks. Its surface features densely cratered areas, plains, and remarkable bright ice cliffs.
Dione orbits Saturn every 2.7 days, at a distance of approximately 380,000 km. For comparison, the Moon (3,476 km across) orbits Earth every 27.3 days, at an average distance of approximately 384,000 km. Intriguingly, two tiny moons share Dione its orbit.
Most of the names of the planetary moons have come from ancient mythologies. In Greek mythology, Dione was a titan and a brother of Cronus (Saturn), the god of agriculture.
References
NASA’s Photojournal
Wikipedia
Aymen Mohamed Ibrahem
Senior Astronomy Specialist