More than eight decades after its discovery

Feb 18, 2010 23:01 GMT  ·  By

First seen on March 19, 1915, the planet Pluto has been the subject of much debate even before it was discovered. While analyzing perturbations in the orbits of Uranus and Neptune, astronomers hypothesized that another celestial body, dubbed Planet X, must be influencing the two. After Pluto was found, the tenth object from the Sun observed directly, it was classified as a new planet. That changed in 2006, when the International Astronomical Union (IAU), with only a minority of members present, declassified it to the dwarf planet class, and named it the largest object in the Kuiper Belt.

In spite of all these debates, the fact of the matter remains that not much is known about this amazing little world. What is accurately known is that the position this body occupies in its orbit cannot be determined for periods of time exceeding 10 to 20 million years, either in the past or in the future. Unlike all other planets, which orbit the Sun inside the ecliptic – a flat reference plane the star generates – Pluto spins on a heavily-inclined orbit relative to the plane, of over 17 degrees. The dwarf planet originated apparently in a population of trans-Neptunian objects, which also marks the beginning of the Kuiper Belt.

Many details about the celestial object will be revealed by the New Horizons NASA spacecraft, currently en route to the outer fringes of the solar system. It will image Pluto in sharp detail and will also conduct investigations of its three moons, Charon, Nix and Hydra. This will advance our knowledge of the celestial object considerably, seeing how the best images of it we currently have, captured via the refurbished Hubble Space Telescope, show mere smudges, and nothing clear. Experts hope that New Horizons will provide the same viewing capabilities that the NASA/ESA Cassini spacecraft provides for Saturn.

Another interesting fact about Pluto is that it has winds, as well as seasons, despite not having an atmosphere to trigger any of them. The dwarf planet also appears to be going through periods of intense global warming, as demonstrated by recent scientific studies. In 2015, when the space probe reaches it, astronomers will finally be able to put a number of theories to the test, including to see whether the body was formed by a collision between two similar-sized Pluto-class objects. There are many astronomers who believe that the moon Charon is actually another dwarf planet, and that Pluto is in fact a binary system, Space reports.