Is Pluto a Binary Planet?

astroengine writes "If the Pluto-Charon system were viewed in a similar way to binary stars and binary asteroids, Pluto would become a Pluto-Charon binary planet. After all, Charon is 12% the mass of Pluto, causing the duo to orbit a barycenter that is located above Pluto's surface. Sadly, in the IAU's haste to define what a planet is in 2006, they missed a golden opportunity to define the planetary binary. Interestingly, if Pluto was a binary planet, last week's discovery of a fifth Plutonian moon would have in fact been the binary's fourth moon to be discovered by Hubble — under the binary definition, Charon wouldn't be classified as a moon at all."

Comments

IAU? Haste? No way.

[girlintraining]

The IAU has been trying to redefine things in bulk, and then growing discontent with those definitions and changing them yet again. It's a far cry from the organization's original role: Cataloging astronomical objects. To put it in perspective, they're like a librarian that changes the layout of the indexing system weekly. They don't actually move the books around, but they rename the aisles, recategorize things, and generally make a massive mess of it all.

But then, I'd expect nothing less from a committee of pseudo-scientists; They're so engrossed with their own administrations they've become cut off from the people they're supposed to be helping.

Re:IAU? Haste? No way.

[Tim the Gecko]

No, it's a hallmark of the bored with too much free time. If you had an employee who spent most of their time recategorizing rather than coming up with something new, would you consider them intelligent? You'd probably think they were lazy or incompetent.

The implication here is that people just got bored and changed things, but really it's just like the planet-to-asteroid naming change in the 1800s. People find a new planet (Ceres/Pluto), and after a while find a whole lot of similar objects. You probably don't want to learn a whole lot of asteroid or KBO names.

Added to this, our notions of Pluto have gradually dwindled from a huge pitch-dark planet, able to perturb the mighty Neptune in its orbit, down to a small bright billiard ball with a gravitational pull only slightly bigger than that of yo' mama.

Re:IAU? Haste? No way.

[chebucto]

true genius is making things simpler.

Or rather, true genius is making things as simple as they can be but no simpler.

Speaking as an amateur, it seems that adding the 'minor planet' category was a reasonable decision. Charon & Pluto are distinct from asteroids, but quite a lot smaller than the rest of the bodies we call planets.

In other fields, we distinguish between islets and islands, streams and rivers, bushes and trees, etc etc etc. Not to add complexity, but to more fully describe reality.

Re:IAU? Haste? No way.

[Anonymous Coward]

Working astronomer here (radio, ground-based). I spend about 2-3 weeks per year actually at an observatory. That's roughly typical in this field, though there's a lot of variation: some people work more on the engineering side and spend 90% of their time on-site, while pure theoreticians might never see a telescope.

Pluto never was a planet

[TheGoodNamesWereGone]

I do not understand at all the rage over Pluto's demotion from planetary status. Is it tradition? 'Traditionally' the Sun was thought to revolve around the Earth. Is it because children have to be sat down and gently told the truth, like about Santa Claus? Is it something more personal between individuals in astronomy? It's called *science* folks, and it's self-correcting. I just don't get why people are so upset.