They say it's no longer a planet, but a "Pluton"... but not forgotten.

Pluton Profile

Mass (kg)                                                    1.29 x 10^22

Diameter (km)                                                       2300

Mean density (kg/m^3)                                            2030

Escape velocity (m/sec)                                         1100

Average distance from Sun (AU)                             39.53

Rotation period (length of day in Earth days)            6.39

Revolution period (length of year in Earth years)     247.7

Obliquity (tilt of axis in degrees)                            122.5

Orbit inclination (degrees)                                     17.15

Orbit eccentricity (deviation from circular)            0.248

Mean temperature (K)                                               37

Visual geometric albedo (reflectivity)              about 0.5

Atmospheric components:    perhaps methane and nitrogen

Surface materials:     perhaps methane ice

More information about Pluto and other "Dwarf Planets" can be found by clicking here.