​diameter of ceres- 950 kilometers
pluto- 2360 kilometers
eris-2400 kilometers

mass of ceres- 2.3 x 10 to the 21 power
pluto-
1.3 × 1022 kilograms
eris-1.67 x 10 to the 22 power


Distance from sun:
eris- 10 billion miles
ceres- 415 million km
pluto- 6000 million km

period of revolution:
eris: 18.84 hours
ceres: 1679.8 days
pluto: 247.7 years

period of rotation:
eris: 557 years
ceres: 1679.819 days
pluto: 248 Earth years

average temp.:
eris: 405 degrees below zero
ceres: x
pluto: between -396°F to -378° F

atmosphere:
eris: frozen to the planet
ceres: does not have one
pluto: has one, made up of water ice

surface materials:
eris: carbon, oxidized meteoritic clay minerals
ceres: rock and has an atmosphere
pluto: Nitrogen, rock, and ice

moons, how many, names:
eris: 1 moon, Dysnomia
ceres: zero
pluto: 3 moons, charon, nix, and Hydra

rings, how many, made of:
eris: zero
ceres: zero
pluto: zero

defining characteristics:
eris: largest dwarf planet
ceres: large dark spot
pluto: Pluto has a density of about two times that of water

hills, valleys, craters, storms:
eris: does not have hills, valleys, craters, or storms
ceres: has craters
pluto: storms and craters

planet discovered:
eris: January 5, 2005 Mike Brown
ceres: January 1, 1801 by astronomer Giuseppe Piazzi
pluto: Feburary 18, 1930 Clyde Tombaugh

got its name:
eris: Eris is named for the Greek goddess Eris, a personification of strife, chaos, and discord
ceres: Roman goddess of the harvest, of growing plants, and motherly love
pluto: Roman god of darkness and the underworld

planet visible from earth:
eris: x
ceres: yes with a telescope
pluto: cannot be seen without a telescope

facts:
eris: rocky core, an icy mantle
Eris The first trans‐Neptunian object found with a diameter larger than that of Pluto; also known as minor planet
ceres:
It is the smallest dwarf planet.
It is the only dwarf planet in the Asteroid belt.
It is too small to see with the naked eye.

pluto: Pluto is the only planet that has not been visited by a spacecraft from Earth. The Pluto Express probe has been delayed.

Pluto was not the farthest planet from the Sun from February 7, 1979 until February 11, 1999 (the order was Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Pluto, and Neptune).