Where'd Pluto Go?

If you're my age, you probably remember learning that Pluto was the ninth planet in the solar system when we were kids, as 75 years of generations had before us. We learned that My Very Excellent Mother Just Served Us Nine Pizzas was a way to remember the order of the nine planets, including Pluto. But as we grow older, we kind of have to catch on that times are changing and we live in the 21st century and Pluto's no longer a planet. But don't worry, Pluto didn't go anywhere, and you'll find out Pluto's current status in today's post!

This is a picture of Pluto [center] that was taken from one of the ‘candidate moons'

You've probably heard that Pluto is now a dwarf planet, and you may (or may not) have any idea what a dwarf planet is. Much to the dismay of many adults that grew up marveling at the forgotten planet, a change to how we label Pluto was made by the International Astronomical Union five years ago. However, some of these same disheartened people still don't understand why scientists would, for example, "make fun of Pluto's size" by naming it a dwarf planet.

Trust me, scientists do not aim to make fun of anything, it's counter productive.

Yet, we find ourselves (as in us, the general public) to become accustomed to misconceptions and whatnot because of the press or just word of mouth. These errors in our perspective also tend to add up, and then leave us in a world far from reality where we have no idea what's going on! This is why I decided to bring up poor Pluto. Let me start with its discovery many years ago:

The Search for Planet X
After our 8th planet Neptune was discovered way back in 1846, scientists began to notice many inconsistencies occurring in the orbit of the gas giants. These inconsistencies led scientists to theorize the possibility of a planet beyond Neptune. Thus, the search for "Planet X" (that's what they called it) begun, and among the most excited was scientist Percival Lowell. Lowell was so excited he built the Lowell Observatory in Arizona; and it was in this same observatory where scientist Clyde W. Tombaugh accidentally discovered Pluto through a sky survey on February 18, 1930.

In 1930, an 11-year old Oxford gal named Venetia Burney had the honor to name the 'forgotten planet' through her well-connected grandpa Falconer Madan, a retired librarian of the Bodleian Library at Oxford. After news of planet's discovery March 1930, Venetia suggested the ‘frozen and lonely planet X' should be named Pluto, after mythical Roman

god of the underworld. Mr. Madan told his friend Herbert Hall Turner, professor of astronomy at Oxford, and passed the notion along at a Royal Astronomical Society meeting. And this person told that person and finally the scientists at Lowell voted in favor of Pluto. Man, wasn't Burney lucky? How would you feel if you got the opportunity to name a [dwarf] planet?!

But, Why Pluto?
Surprisingly enough, for centuries astronomers and common folk alike had been admiring the 'bright lights' of the night sky without wondering what they've actually been looking at. Yes, they knew there were stars and planets and such above them, but there wasn't a concrete definition of what actually constitutes a planet. As our technology has become more advanced over time, so did our outlook on, well, everything. Suddenly, more objects beyond Neptune like Pluto were being discovered (because of modern tech) and some were found to be larger in mass than Pluto...but weren't planets. Scientists have known about Pluto's illegitimacy as a planet because of its small size for years...but now, when the means were finally available, it was time to do something about it.

In 2006, the IAU, which is responsible for classification of things up in space, decided to update the understanding of planets in our solar system by writing solid definitions (in this resolution) for the word "planet" and "dwarf planet." This is important because by definition, Pluto was really a dwarf planet...it makes sense.

A planet is an object in space that (a) is in orbit around the Sun (b) has enough mass to stay round due to gravity and (c) doesn't have anything else going around in its same orbit.

A dwarf planet is an object in space that is similar to a planet except (a) it has other things going around in its orbit, and (b) is not a satellite.

And that's the story of Pluto! Children nowadays are learning a new mnemonic: My Very Excellent Mother Just Served Us Nachos. Hey, if Tyche is discovered, the mnemonic might as well continue the Mexican cuisine theme with Nine Tacos, right? For now, I'd like to pose two discussion questions:

1. Why's it necessary for scientists and the general public to re-evaluate their claims?
2. Why would scientists let a young girl name a planet? Do you think someone has to be 'qualified' to uphold such a task? Why Venetia Burney, and not, for example, the President of the United States?

Image #1 credit: NASA
Image #2 credit: NASA; (HST picture)

References:

"Dwarf Planets." National Geographic. (Check out this link for a really cool interactive about Pluto and Dwarf Planets! Find out your weight on Pluto! I'd be 7 lbs or about 3 kg)

O'Neill, Ian. "Does a Massive Planet Lurk in the Outer Solar System?" Discovery News. February 16, 2011. (Read this article about the planet that might replace Pluto! Tyche!)

"Pluto and The Developing Landscape of Our Solar System" Internatonal Astronomical Union.

"Pluto discovered." The History Channel.

"RESOLUTION B5: Definition of a Planet in the Solar System" International Astronomical Union.

"Venetia Phair Dies at 90; as a Girl, She Named Pluto ." New York Times.