A ring system is a disc or ring, orbiting an astronomical object, that is composed of solid material such as dust and moonlets, and is a common component of satellite systems around giant planets like Saturn. A ring system around a planet is also known as a planetary ring system.
The ring orbiting Saturn consists mostly of chunks of ice and dust. The small dark spot on Saturn is the shadow from Saturn's moon Enceladus.
A Galileo image of Jupiter's main ring.
A Cassini mosaic of Saturn's rings.
A pair of Voyager 2 images of Neptune's rings.
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists within the observable universe. In astronomy, the terms object and body are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial object is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures.
Composite image showing the round dwarf planet Ceres; the slightly smaller, mostly round Vesta; and the much smaller, much lumpier Eros
Image: 243 ida
Image: Mimas Cassini
Image: Portrait of Jupiter from Cassini
