Tech & Biz

Is Pluto a Planet Again?

by Jordan Yerman | December 18, 2009 at 02:08 pm

26248 views | 43 Recommendations | 15 comments

Is Pluto a planet again? Yes and no. While the International Astronomical Union does not consider Pluto a planet, it's counterintuitive to think of it as just a giant asteroid. The IAU considers Pluto a "dwarf planet", which is sort of like being on the junior varsity team: you're still on the team, but you don't get cheerleaders or your name in the local paper.

Back in the day, there were two types of planets: rocky worlds (like Earth and Mars) and gassy giants (like Saturn and Jupiter). But what if Pluto isn't a non-planet, but a third type of planet? As we see more and more of the universe around us, we're forced to rethink the concept of the planet. For example, what about a potential ocean-world like GJ 1214b (I prefer "Planet Zarkon", but hey)? "It's a planet, Jim, but not as we know it..."

Pluto has not changed; only our perception has changed. I bet it's only a matter of time before Pluto gets to ditch its numerical moniker and rejoin its celestial brethren. "Dwarf planet", indeed! Surely a planet of small stature is still a planet.

Pluto isn’t the ninth of nine; it’s the first of many. Thanks to the discoveries of the past couple of decades, we’ve gained a whole new tribe of worlds to watch in the Kuiper Belt, and the vast, diffuse Oort Cloud represents an even farther frontier we haven’t yet begun to explore.

Incidentally, the State of Illinois is keeping the faith, and still considers Pluto a planet.

MEanwhile, NASA is organizing a surprise inspection:

NASA's New Horizons spacecraft, launched in 2005, will arrive at Pluto in 2015.

Look busy, Pluto.

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Uwe Paschen

at 17:03 on December 18th, 2009

Laurel Kornfeld (not verified)

at 23:37 on December 18th, 2009

You got it exactly. Dwarf planets are planets too--a third class of planets in addition to the terrestrials and jovians.

M. Holmes (not verified)

at 17:58 on December 19th, 2009

Surely a planet of small stature is still a planet. Absolutely.

Joey Joe Joe Jr. Shabadu (not verified)

at 09:36 on January 14th, 2010

If Pluto is a Planet, then you have to include all the other Plutoid Planets (Planets in Orbit around the Sun, further than Neptune). Pluto, Eris, Haumea, and Makemake have all been identified as Plutoid planets. So, either there are 8 or 12 planets. Not 9. Take your pick.

Joey Joe Joe Jr. Shabadu (not verified)

at 09:56 on January 14th, 2010

Make that 13 Planets, I forgot about Ceres (which was thought of as the 8th planet back in the 1800s)

ceciliaailicec (not verified)

at 14:52 on February 7th, 2010

the more the merrier.

ani azubike nicodemus (not verified)

at 08:08 on January 16th, 2010

earth and mars which of the two planets is the hottest, please send this to my email box. Pluto is not the smallest i think mercury should be the smallest.