We nervously await the decision of the International Astronomical Union, which asked a relatively simple question and then came up with an amazingly complicated answer.
The question: Is Pluto really a planet?
The answer: Well, it is – if you come up with multiple new definitions of planets, divide them into two categories and create one category just for Pluto and other smallish spheres in our solar system with elliptical orbits.
Meeting in Prague next week, the experts will weigh a proposal to add three new planets – for a total of 12.
If the proposal stands, schoolchildren will no longer be able to memorize the planets of the solar system using such simple acronyms as “My Very Easy Method Just Showed Us Nine Planets.”
Pluto doesn’t look or behave like Earth or the other seven “old” planets. Its orbit is elliptical and not in the same plane as the orbits of other planets. It’s merely a one-fiftieth of the mass of Earth.
Other objects with orbits like Pluto have been discovered in a yard of icy debris beyond Neptune called the Kuiper Belt. Thus, many astronomers have argued that it would be more logical to classify Pluto as a Kuiper Belt object instead of a planet.
Eventually, some loyal schoolchildren protested against Pluto’s possible removal from the list of planets. If only they knew the can of worms they were about to unleash.
The International Astronomical Union sought to resolve the matter by creating a task force to develop a new definition of what constitutes a planet. The group deadlocked and gave way to a new committee that agreed unanimously on a concept few will be able to remember as we gaze upon the heavens.
The recommendations revolve around two categories:
1. The Big Eight (all the planets listed now excluding Pluto) fulfills this definition of a “classic planet” – an object that has a circular orbit inside the “typical” orbital plane and takes less than 200 years to complete.
Ceres, which is between Mars and Jupiter and is the largest asteroid, would join that list.
2. The planets lite, labeled “plutons,” are smaller objects that move in tilted orbits around the sun and take longer than 200 years to make the trip. Pluto is considered a pluton, along with “the 10th planet,” 2003 UB313 (more commonly known as Xena), and Pluto’s large moon, Charon.
As space science improves, astronomers can and surely will come up with a list of planets that no student could memorize.
