Is Pluto A Planet? A Tribute To Clyde Tombaugh

Is Pluto a planet? There are apparently three answers depending on who you talk to: Yes, No and Maybe. So, what do YOU think? Do you have an opinion on this recent controversy? But more importantly, why? What is your basis for your answer? Why do you think Pluto either is, isn't or possibly could be a planet?

The IAU (International Astronomical Union) in 2006 voted to downgrade Pluto from it's former 'Planetary' status. Now many in the astronomical community not only disagree, but have vowed to ignore the IAU's recent decision. Pretty intense stance, don't you think?

Why the intense feelings? Why such harsh posturing over a tiny object that is almost four billion miles away from the Sun?

In 1906, Percival Lowell, a wealthy Bostonian who founded the Lowell Observatory in Flagstaff, Arizona, began an extensive project in search of a ninth planet, named "Planet X". You see, something had been messing with Uranus' and Neptune's orbits and the only reasonable explanation was that yet another planet's gravity must be causing the chaos. So the search for "Planet X" was on. Percival Lowell spent the remainder of his life searching for this hypothetical object - which he never found. Lowell died in 1916 at the age of 61. His project was put on hold... indefinitely.

In 1929, 23 year old Kansas farm boy, Clyde Tombaugh, got a job at the Lowell Observatory, cleaning up after astronomers and doing various odd jobs. His interest in astronomy led to a new job of continuing the search for Lowell's "Planet X". He did this by systematically taking photographic images of identical portions of the night sky, two weeks apart and then comparing the photographs with something called a "blink comparator" - it enabled him to quickly switch back and forth between photographs in order to detect any moving objects. Then, in 1930 on February 18th, Clyde found something.

What is a planet? Until 2006, there was only the ancient definition. The word planet comes from the Greek word for "wander". Back in ancient times, when Earth was the center of the Universe, our ancestors noticed that seven lights moved, or wandered, through the sky - the Sun, the Moon, Mercury, Venus, Mars, Jupiter and Saturn. This is why we have seven days of the week, by the way. If you know your Latin based languages, you can figure out which planet is which day. I'll give you a hint: Sunday is the Sun, Monday (or Lunes, Luni, etc.) is the Moon, Tuesday (or Martes, Mardi, etc) is Mars, Wednesday (or Miercoles, Mercredi, etc) is Mercury, and so on... can you guess which day is represented by Venus? and Saturn?

Obviously, we don't consider the Sun and Moon as planets any longer, but for more than 15 centuries, we did. Imagine how freaked out people were when Nicholas Copernicus suggested (and Galileo Galilei proved) that Earth was NOT the center of the universe - that, in fact, the SUN was the center of it! Many people died - burned alive at the stake by the Catholic Church - for suggesting this. Galileo, who insisted that the authorities look through his telescope and "see for themselves", wasn't murdered. Instead he was put under house arrest for his discoveries. He died in 1642 - blind from observing the Sun, still imprisoned by the church.

The Catholic Church did finally apologize to Galileo... in 1992. Seriously, 1992.

In March of 1930, as word of Tombaugh's discovery spread across the globe, Venetia Burney, an eleven year old school girl in Oxford, England, interested in astronomy and classical mythology, suggested to her Grandfather that the new planet's name should be "Pluto", after the Roman God of the underworld. On March 24th, 1930, the ninth planet in our Solar System was named. Tombaugh became a celebrity, and to this day, remains so. An uneducated farm boy from Kansas - the first American to discover a planet! "Local Boy Becomes A Hero!"

Today, Tombaugh is immortalized in a stained glass window in the Unitarian Universalist Church of Las Cruces, New Mexico. Though not a religious person, I feel it's wonderful that religion and science are able to co-exist with each other, rather than certain, divisive, ideology prevalent in some of today's pro-religion/anti-science communities. To me, this is another way Tombaugh is a hero.

Pluto is far away. Really far. It's so far that we don't have any good pictures of it. Even the Hubble Space Telescope can't get a good, detailed snapshot of it. After it's discovery, speculation was that it was huge, but as more observations happened and as technology improved over the years, astronomers eventually realized that Pluto was tiny. Today we know that it's only one fifth the size of Earth's moon.

We also know that Pluto doesn't orbit the Sun in the same way as the other planets. Pluto's orbit is so eccentric that it actually crosses Neptune's orbit - no other planet does that. Pluto's orbit is also tilted - and not just slightly like Mercury's - it's a full seventeen degrees off the plane of the ecliptic. It also isn't alone... there are thousands, perhaps millions of other rocky, icy objects in it's neighborhood - what's now called the Kuiper Belt. Eris, which is bigger than Pluto, is another discovery in this belt. Does that mean that Eris is the tenth planet in our Solar System?

Could it be possible that, now that technology is slowly catching up to discovery, what we thought was a planet is just one of thousands of newly discovered bodies in a vast belt of icy objects? What about the Asteroid Belt between Mars and Jupiter? Should the objects in it be considered planets as well?

Astrophysicist Dr. Neil deGrasse Tyson became the unintended center of a controversy firestorm when, during the exhibit design and construction of the Hayden Planetarium in New York, he decided to group the planets in our Solar System based on their physical properties, rather than their locations relative to one another. For instance, the four terrestrial, rocky planets - Mercury, Venus, Earth and Mars, are placed together. In a separate area, the gas giants are placed together - Jupiter, Saturn, Uranus and Neptune. And finally, the icy, rocky objects in the Kuiper Belt are placed together - and Pluto is there. One day while overhearing a young child ask his mother, "Mom, where's Pluto?", a New York Times reporter broke the story that made his paper's front page and changed Dr. Tyson's life - "Pluto Not A Planet? Only In New York". Again, on the front page of the New York Times, right under the story of George W. Bush's inauguration! Dr. Tyson's mail box was flooded with hate mail - a lot of which came from angry third graders.

What is a planet? According to the IAU, for an object to be a planet it must meet three criteria: 1) it must orbit the sun, 2) it must be big enough for it's gravity to force it into a spherical shape and 3) it must have cleared it's orbit of debris. Although Pluto meets the first two criteria, it doesn't even come close to #3. As a result, Pluto was classified as a smaller object, something called a "Dwarf Planet". This brings up an interesting point - one shared by many astrophysicists and other planetary scientists: 'a chihuahua may be a small dog, but it's still a dog nonetheless'.

Which brings us back to our original question - is Pluto a planet? Again, it seems that the answer to that question depends on whom you talk to. At this point, we really don't know enough about Pluto to come up with an answer that will satisfy everyone. That, however, is about to change. In January of 2006, NASA launched "New Horizons", which is on it's way to do a fly-by of Pluto in early 2015. This small spacecraft will be the first to ever get a detailed look at the distant, icy sphere. It's equipped with three special cameras to capture details of the surface, it's make up and possible ring system. It will approach and pass Pluto, Charon, Nix, Hydra, finally Eris and then keep going, never to return back home. After the photographs are sent, after the data is analyzed, after the mission is complete, New Horizons will continue on into the vast, cold, dark emptiness of space until one day, it'll simply be a memory...

Technology is amazing. Eighty five years after a 23 year old farm boy from Kansas discovered what was once the ninth planet in our Solar System, we will finally begin to have details of this beloved yet controversial object. As fascinating as this may be, to me the most important detail of this remarkable nine year journey is that some of Clyde Tomabugh's remains - his ashes - were placed aboard the New Horizons spacecraft and are now headed to the celestial body that he discovered eighty years ago.

Whether Pluto is a planet or not isn't that important to me anymore. What I find most intriguing is that the Kansas farm boy who discovered Pluto, is on his way to find out for himself. I can't imagine a more fitting tribute.

Thank you, Clyde.