Pluto: The Dark Planet

Pluto is the farthest planet in our solar system from the sun. It was discovered through mathematics before there were telescopes. Pluto is about 39 times as far from the sun as earth is. It takes 248 earth years to orbit the sun, in twenty of them in moves inside Neptune's orbit becoming the eight planet from the sun for that period. It is currently inside Neptune's orbit and will remain that way until March 15, 1999. (the picture is an artist's rendition, not an actual photograph)

General information on Pluto:

• Diameter (miles)= 1,420
• Mass (trillion trillion lbs)= .026
• Density (earth=1)= .36
• Gravity (earth=1)= .0637
• Period of Rotation (hours)= 6.4
• Escape Velocity (mph)= 2,640
• Major Atmospheric Gas= Methane
• Inclination of Equator (degrees)= 62
• Known Moons= 1
• Mean Orbital Velocity (mph)= 10,604
• Minimum Distance From Sun= 2,756 (millions of miles)
• Maximum Distance From Sun= 4,555 (millions of miles)
• Mean Distance From Sun= 3,656 (millions of miles)
• Period of Revolution (earth years)= 247.70

Detailed information on Pluto:

Unfortunately, very little is known about the planet Pluto because of its great distance from the earth. It has an estimated diameter of 4,000 miles which is about half of earth's. The temperature on Pluto may be as low as -360 degrees Farenheit. In 1905, it was discovered that some gravitational force seemed to be affecting the orbits of Neptune and Uranus. Percival Lowell, and American astronomer predicted that it was a new planet. Pluto is the only planet that has not been visited by any spacecraft and even the Hubble Telescope can only pick up the major features of Pluto's surface.

Composition--

The actual composition of Pluto is unknown but it is believed that the planet is about 70% rock and 30% water ice like Triton. Pluto has bright and dark areas on its surface. It is thought that the bright areas are covered by ices of nitrogen as well as smaller amounts of methane and carbon monoxide. The dark areas may be due to some sort of primordial organic material or photochemical reactions caused by cosmic rays.

Atmosphere--

Again, little is known about the atmosphere of the Dark Planet. For the majority of the planet's long year the atmospheric gases are frozen into ice. These gases are probably nitrogen with some methane and carbon monoxide.

Theories--

Due to Pluto's unusual orbital pattern, much like Triton (satellite of Neptune), it was once believed that Pluto may have been a moon to Neptune but this is now generally ruled out. The more generally accepted belief is that Triton was once like Pluto was captured in Neptune's gravitational force. Perhaps Pluto, Triton and Charon were once part of a class of objects that were separated by some force. The recent discovery of planetary-like objects beyond Pluto may help support this theory.