The Ninth Planet..., or not

My concept of Tyche

(Space.com) Since the 2006 reclassification of Pluto by the International Astronomical Union, our solar system has to make do with “only” eight planets. This situation, however, may soon change.

For over a decade, astrophysicists John Matese and Daniel Whitmire from the University of Louisiana have suggested the possibility of another planet. The two hypothesized that the odd orbital paths of some comets could be explained by the gravitational field of a ninth planet—approximately four times the size of Jupiter—in the so called Oort Cloud, which marks the boundary of our solar system about one light year from the sun. The two scientists call this, so far fictional, planet Tyche, named after the Greek god of luck.

Very exciting right? Well, not everyone thinks so…

Most other experts, including lead astronomers at Harvard and Southwest Research Institute, think that, though the idea is theoretically plausible, the chances for such a planet to exist are slim at best. Worse yet, there is no concrete evidence, only theories—most recently a study published in the American Astronomical Society's scientific journal, Icarus.

On the other hand, Matese and Whitmire are optimistic, claiming that NASA’s WISE telescope may already have the much needed proof. Finding the evidence in the telescope’s vast database—if it is even there—however, may take years after the data goes public in April, 2011.

But, the story does not end there. Should such discovery occur, the classification of Tyche will still depend on the IAU.

External links: NASA FAQ