Cassini Regio [SEP] located on astronomical body
Cassini Regio
Cassini Regio is the enigmatic dark area that covers the leading half of Saturn's moon Iapetus. It is named after Giovanni Cassini, the discoverer of Iapetus; 'Regio' is a term used in planetary geology for a large area that is strongly differentiated in colour or albedo from its surroundings. The brighter half of Iapetus is composed of the Roncevaux Terra and the Saragossa Terra.
The nature of the material that caused the extensive discoloration of Cassini Regio is not known, but it appears to be quite thin
current system was adopted by the International Astronomical Union, the body which oversees planetary nomenclature.
The longitudes of physical features on Venus are expressed relative to its prime meridian. The original prime meridian passed through the radar-bright spot at the centre of the oval feature Eve, located south of Alpha Regio. After the Venera missions were completed, the prime meridian was redefined to pass through the central peak in the crater Ariadne.
Physical characteristics Surface geology.
Much of the Venusian surface appears to have been shaped by volcanic