Ceres is about the size of Texas. Though it comprises 25% of the total mass of the asteroid belt, it still is smaller than even the tiny Pluto, 14 times smaller.

Though it is not considered a planet, it shares some of the characteristics of rocky planets like Mars. Ceres is believed to have a differentiated interior. Which means, it's more dense at the core than at the surface.

Ceres is believed to possibly have more water than the amount of fresh water on earth. It is believed so because Ceres is less dense than the surface of earth, and surface bears evidence of water-containing minerals. No direct evidence yet exists that Ceres contains water indeed.

Ceres was discovered by Sicilian astronomer Father Giuseppe Piazzi. He spotted the object as he was looking for a suspect planet between Mars and Jupiter. When he found it, he called it a planet. Later, it was classified as an asteroid. In 2006, it was promoted to the status of a dwarf planet, in line with Pluto and Eris. in recognition of its planet-like characteristics.

The Facts

Discovered By

Giuseppe Piazzi

Date of Discovery

1 Jan. 1801

Orbit Size Around Sun (semi-major axis)

Metric: 413,690,250 km

English: 257,055,204 miles

Scientific Notation: 4.1369025 x 108 km (2.7653485 x 100 A.U.)

By Comparison: Earth is 1 A.U. from the Sun

Perihelion (closest)

Metric: 380,951,528 km

English: 236,712,305 miles

Scientific Notation: 3.80952 x 108 km (2.547 x 100 A.U.)

Aphelion (farthest)

Metric: 446,428,973 km

English: 277,398,103 miles

Scientific Notation: 4.46429 x 108 km (2.984 x 100 A.U.)

Orbit Circumference

Metric: 2,595,217,959 km

English: 1,612,593,677 miles

Scientific Notation: 2.595 x 109 km

By Comparison: 2.761

Average Orbit Velocity

Metric: 64,360 km/h

English: 39,991 mph

Scientific Notation: 1.7878 x 104 m/s

By Comparison: 0.600

Orbit Eccentricity

0.079138251

Orbit Inclination

10.59

Mean Radius

Metric: 476.2 km

English: 295.9 miles

Scientific Notation: 4.7620 x 102 km

By Comparison: 487.3 x 454.7 km oblate spheroid

Equatorial Circumference

Metric: 2,992.1 km

English: 1,859.2 miles

Scientific Notation: 2.99205 x 103 km

By Comparison: 0.0747

Volume

Metric: 452,331,448 km3

English: 108,520,085 mi3

Scientific Notation: 4.52331 x 108 km3

Mass

Metric: 947,000,000,000,000,000,000 kg

Scientific Notation: 9.47 x 1020 kg

Density

Metric: 2.09 g/cm3

Surface Area

Metric: 2,849,631 km2

English: 1,100,249 square�miles

Scientific Notation: 2.8496 x 106 km2

Surface Gravity

Metric: 0.28 m/s2

Escape Velocity

Metric: 1,855 km/h

Sidereal Rotation Period (Length of Day)

0.378 Earth days

9.07417 hours

By Comparison: 0.38

Sources:

"Ceres", http://solarsystem.nasa.gov/planets/profile.cfm?Object=Dwa_Ceres