Pluto

Planet Profile

Diameter (km)........................................2300
Mean density (g/cm^3) ...............................2.03
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

Mean temperature (K).................................37

Atmospheric components...............................perhaps 
                                                     methane and 
                                                     nitrogen 
Surface materials....................................perhaps 
						     methane ice

  Clearest View

This is the clearest view yet of the distant planet Pluto and its moon, Charon, as revealed by NASA's Hubble Space Telescope. The image was taken by the European Space Agency's Faint Object Camera on February 21, 1994 when the planet was 4.4 billion km (2.6 billion mi) from Earth. Hubble's  optics show the two objects as clearly separate and sharp disks. This has allowed astronomers to measure (to within about 1 percent) Pluto's diameter of 2320 km (1440 mi) and Charon's diameter of 1270 km (790 mi). The Hubble observations show that Charon is bluer than Pluto. This means that both worlds have different surface composition and structure. A bright highlight on Pluto suggests it has a smoothly reflecting surface layer.