Posted by Vicki Sieglen on 24 Aug 2006 at 2:20 pm.
Filed under Astronomy.
Over the last two weeks, The International Astronomical Union as been discussing, in Prague, The Czech Republic, about the redefinition of the word planet, as well as the fate of Pluto.
The new definition of the word planet is as follows: A) The object in question has to orbit the Sun. B) The object has to be large enough that its own gravity will pull the object into a nearly spherical shape. C) The object has to have cleared out the neighborhood around its orbit.
According to this new definition of the word planet, our solar system will have eight classical planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Pluto will lose its planetary status. Pluto loses it status because it can’t meet the last requirement for being considered a planet. Pluto’s orbit, for a time, carries it inside the orbit of Neptune, there for Pluto hasn’t cleared the neighborhood around its orbit.
This new definition now forms a new category for classifying the small bodies of the solar system. Pluto and UB313, also nick named Xena by the discoverer, will be considered dwarf planets. This definition keeps with astronomy lingo, meaning that word dwarf is used for objects that fall in between definitions. For example the term brown dwarf refers to an object that as a low mass and can’t operate like a normal star. Pluto will still be important though, it will be used as a prototype for dwarf planet status.
Michael Brown from the California Institute of Technology and also the discoverer of UB313 (Xena) stated to Sky and Telescope magazine that he was glad Pluto and similar objects didn’t receive planetary status. Brown believes:
It would have taken the magic out of the solar system.
Lance on 19 May 2007 at 2:13 pm: 1
Is that image a scale representation of all the planets?