Ceres (dwarf planet)

Ceres symbol (bold)

Ceres symbol (fixed width)

Ceres 'C' symbol

Ceres Orbit c

File:Permanent Shadows on Ceres.webm

PIA20918-Ceres-Dawn-GlobalMap-Annotated-20160926

Ceres (dwarf planet) is the largest object in the asteroid belt that lies between the orbits of Mars and Jupiter. With a diameter of about 940 kilometers, Ceres comprises approximately a third of the asteroid belt's total mass. Discovered on January 1, 1801, by Giuseppe Piazzi, it was the first asteroid to be identified. Initially considered a planet, Ceres was later reclassified as an asteroid and, in 2006, as a dwarf planet by the International Astronomical Union (IAU).

Discovery and Naming

Ceres was discovered by Giuseppe Piazzi at the Palermo Astronomical Observatory. He initially thought it was a new planet. The name Ceres comes from the Roman goddess of agriculture, grain crops, fertility, and motherly relationships.

Physical Characteristics

Ceres is notable for its spherical shape, which distinguishes it from most other objects in the asteroid belt that are irregularly shaped. This spherical shape, along with its differentiation into a rocky core and icy mantle, qualifies Ceres as a dwarf planet. The surface of Ceres is composed of a mixture of water ice and various hydrated minerals like carbonates and clay. It has a thin atmosphere that may contain water vapor, a result of ice sublimating from its surface.

Surface Features

The surface of Ceres is marked by craters, mountains, and bright spots that have attracted considerable attention from astronomers. The bright spots, particularly those in the Occator Crater, are believed to be deposits of sodium carbonate and other salts, left behind when briny water from Ceres' interior reached the surface and evaporated.

Orbit and Rotation

Ceres orbits the Sun at an average distance of 2.77 astronomical units (AU), taking about 4.6 Earth years to complete a single orbit. Its axial tilt is relatively small, about 4 degrees, which means it does not experience significant seasonal changes.

Exploration

The most significant exploration of Ceres has been by the Dawn spacecraft, which was launched by NASA in 2007. Dawn entered orbit around Ceres in March 2015, making it the first spacecraft to visit a dwarf planet. The mission provided valuable data on Ceres' surface composition, topography, and internal structure until it concluded in November 2018.

Significance

Ceres is of great interest to scientists for several reasons. Its status as a dwarf planet in the asteroid belt makes it a unique object for study in understanding the early solar system. The presence of water ice and potential for harboring briny water beneath its surface suggests that Ceres could be a target for future missions that seek to understand the possibility of life in the solar system.