From its eminent status as one of the nine - the elite group of planets in our solar system - to its classification as a mere dwarf planet, Pluto has taken quite a shot to its reputation in recent years. Named after the god of the underworld and occupying a dusty, shadow-filled zone packed with comets and asteroids, perhaps Pluto never deserved a better fate. However, its effects on Neptune and Uranus made it one of the solar system's most influential worlds.
Understanding the Character of Pluto
Pluto is different from the large planets mainly in size and distance from the Earth. Because it is so far away and shrouded in darkness, Pluto draws less observation. Still, astronomers know that it has a diameter of less than 20% that of the Earth and contains a great deal of ice sheets, composed of methane and nitrogen in addition to hydrogen. It is a freezing place, even when its orbit takes it closer to the sun, but it remains so far away from the light and heat of the great star to average temperatures below -350 degrees on its surface.
The Orbit of the Fallen Planet
Pluto may have lasted so long as a major planet because of the extreme duration of its orbit. Taking some 248 years to complete its orbit of the sun, Pluto was seen as closer than Neptune is. However, as the orbit continued and astronomers continued to track Pluto's path through the solar system, they noticed it had gone beyond Neptune, back to the cold corner of space no planet has ever been seen to inhabit. Chances for observation are brief because of this dramatic orbital path.
The Duet of Charon and Pluto
Among the interesting features of Pluto, perhaps most intriguing is the relationship to Charon, its prominent moon. Charon is about half Pluto's size and, since its relegation to dwarf planet status, many astronomers think of the duo in tandem. In fact, they are only approximately 12,000 miles apart - the distance of a manageable flight for most humans. Were life possible on this planet, explorations to the moon would surely be more convenient and frequent than human beings in relation to the moon.
Though they are similar in size and position in the solar system, Charon and Pluto diverge in many aspects. While Pluto looks reddish to the eye and is dominated by nitrogen and other gases like methane, Charon has more of a grayish appearance - possibly due to the presence of hydrogen-packed ice formations. Still, they are locked in retrograde orbit (as is Neptune and its moon Triton).
Learning More about the Kuiper Belt
The double dwarf planets Pluto and Charon reside in an area known to scientists as the Kuiper Belt, where several other moons have been discovered. Identified as moons of Pluto, Hydra and Nix are far smaller than even the dwarf planets: 30 miles in diameter by some estimates. As Hubble telescope observations continued, two more moons were discovered. Much more information could arrive in the coming years, as an exploration already launched plans to get its closest in the year 2015.
Until then, our knowledge of the goings-on within the Kuiper Belt will rely on single discoveries. Astronomers and amateur stargazers will likely wait with baited breath as more information on these dwarf planets comes into our hands.