Night Owls

OffByOne · OffByOne, as of 16 Aug 2006 at 05:04 GMT

It is Wednesday morning now, so the official draft should be made public quite soon. Fabricating geopolitical conspiracies regarding seven academics drafting a taxonomic definition is entirely absurd. Let us simply inspect the published criteria once they appear.

kookaburra99 · kookaburra99, as of 16 Aug 2006 at 05:56 GMT

checking the news every five minutes this arvo, fingers crossed the criteria are kind to pluto.

quasistatic · quasistatic, as of 16 Aug 2006 at 06:18 GMT

The draft text has just been reported this morning by Space.com, and it is rather extraordinary. The committee proposes that any object orbiting a star is a planet provided it has sufficient self-gravity to be round, and is not itself a satellite.

Under that rule, the immediate count rises to twelve. Ceres becomes a planet again, as does 2003 UB313, and remarkably, Charon is included because the barycentre of the Pluto-Charon system sits in open space between them rather than inside Pluto.

This completely sidesteps the dynamical question. Instead of asking whether an object has cleared its orbital zone, the panel has chosen an entirely hydrostatic criterion. Mike Brown has already described the result as a complete mess, pointing out that dozens more bodies in the Kuiper belt will qualify as soon as their shapes are confirmed, whereas Alan Stern supports it. Alan Boss remarked that it reads as though it were drafted by lawyers rather than scientists, and I must say I see his point. It looks far more like a political compromise to keep Pluto than a sensible physical classification. We shall see how the wider assembly receives it.

OffByOne · OffByOne, as of 16 Aug 2006 at 06:24 GMT

Strictly speaking, 2003 UB313 cannot yet be called a planet in any formal sense until the assembly actually ratifies this text next week.

That said, I find the published wording deeply disappointing. By relying entirely on hydrostatic equilibrium - essentially whether self-gravity has pulled a mass into a nearly round shape - the committee has constructed a purely geophysical threshold while ignoring orbital dynamics altogether. A genuine astronomical classification cannot simply disregard how a body interacts with its orbital environment. Alan Boss is quite right that this reads like an unscientific legal compromise, drafted specifically to preserve Pluto's historical status without explicitly stating so.

If roundness alone suffices, Mike Brown's observation that dozens of additional trans-Neptunian objects will qualify is mathematically unavoidable. We are trading one historical anomaly for taxonomic chaos. A definition ought to clarify reality, not obscure it with artificial legalisms, and I suspect the wider assembly will find this compromise rather hard to stomach.

PintOfMild · PintOfMild, as of 16 Aug 2006 at 08:19 GMT

Twelve of them! That is brilliant news, Pluto lives to fight another day! Though trying to make up a rhyme to fit Ceres, Charon and Xena in there is going to give me a proper headache over my tea break. My Very Educated Mother Just Served Us Nine... what on earth starts with C, P, C, X? Pizzas, Cheese and Extra crisps maybe? Sounds like a good pub lunch to me! Anyone fancy a pint in the Victoria Commercial next Thursday to celebrate? Cheers!

Sysop_Kev · Sysop_Kev, as of 16 Aug 2006 at 08:44 GMT

Grand so, twelve it is for now. Adding three names to the list just shows it was pure admin all along. They drew a circle around round rocks to keep everyone happy, but the sky looks the exact same this morning. Let them argue over the paperwork next week.

kookaburra99 · kookaburra99, as of 16 Aug 2006 at 09:27 GMT

Twelve planets sounds wild, but I am honestly so thrilled Pluto is still on the list! Having a round shape seems like a pretty straightforward physical rule to explain to people, even if making Charon a full twin planet is going to take some getting used to. PintOfMild, that lunch rhyme is gold! But OffByOne and quasistatic make a really good point about the orbits. If ignoring orbital dynamics means there could suddenly be dozens more trans-Neptunian objects joining the club, I wonder if the rest of the astronomers in Prague will actually vote for it next week. It definitely feels like things might get messy before Thursday.

OffByOne · OffByOne, as of 16 Aug 2006 at 10:13 GMT

The issue is that the proposed resolution creates a very messy precedent. By treating hydrostatic equilibrium as the sole determinant, the committee has effectively discarded the astronomical context in favour of geology alone.

Consider the practical ramifications of the footnotes. If shape alone qualifies a body, then Ceres is merely the first asteroid to re-enter the catalogue. Bodies such as Pallas, Vesta, and Hygiea are already noted as potential candidates should further observations show they achieved equilibrium. In the outer solar system, the situation becomes unmanageable very quickly. There are already dozens of trans-Neptunian objects with diameters suggesting sufficient mass for roundness. If we must elevate every distant ice ball to full planetary status simply because its gravity smoothed its edges, the term ceases to convey meaningful structural information about our solar system.

A sensible taxonomy must describe how a body dominates its neighbourhood. An asteroid belt or a swarm of Kuiper belt objects is a distinct dynamical phenomenon from a major planet. I suspect many planetary astronomers in Prague will see this draft for what it is, an unworkable administrative fix designed purely to placate sentimental attachments.

TheyKnow · TheyKnow, as of 16 Aug 2006 at 13:46 GMT

Don't pop the corks just yet, folks... The committee knew the public and NASA would never swallow an outright demotion, so they drew up this twelve-planet list to take the heat off. But look at how fast the knives are coming out now! You already have folks calling it a 'mess' and grumbling about orbits and Asteroid Belts before the ink is even dry... That is the real PLAY here, mark my words. They put out a draft designed to look unworkable, just so the assembly has an excuse to tear it down next week and kick Pluto out the back door anyway. Keep your eyes open...

kookaburra99 · kookaburra99, as of 16 Aug 2006 at 13:48 GMT

TheyKnow wrote:

They put out a draft designed to look unworkable, just so the assembly has an excuse to tear it down next week and kick Pluto out the back door anyway.

sorry if this is a dumb question, but is everything really a conspiracy lol? i reckon seven professors probably just spent months trying to find a neat physical formula so everyone could agree, not hatching some secret plot to trick everyone!!

that said, OffByOne's point about the asteroids makes heaps of sense to me. if being round is the only test, having to call Vesta, Pallas and dozens of frozen rocks planets does seem super chaotic for science teachers to keep up with. it's awesome pluto survived the draft, but ignoring how they orbit really might make the whole assembly push back next week.

Punchcard · Punchcard, as of 16 Aug 2006 at 15:17 GMT

kookaburra99 wrote:

i reckon seven professors probably just spent months trying to find a neat physical formula so everyone could agree, not hatching some secret plot to trick everyone!!

Young lady, you have put your finger on it. The committee has merely offered its first draft of the rules, relying on gravity and roundness to draw a clear line. There is no trickery in that, only an attempt to be fair. We should wait patiently to see how the wider assembly votes next week before deciding it is settled.

kookaburra99 · kookaburra99, as of 16 Aug 2006 at 15:58 GMT

Punchcard wrote:

We should wait patiently to see how the wider assembly votes next week before deciding it is settled.

totally agree, thanks Punchcard! sorry if i sounded impatient before, still getting used to posting here lol. it really is just down to whether the assembly wants a simple physical rule or if the orbit argument wins out. going to be so fascinating watching the debate unfold!

Sysop_Kev · Sysop_Kev, as of 16 Aug 2006 at 16:43 GMT

Dead right, wait and see is the only sensible play. It is just committee members haggling over filing cabinets and dictionary entries, not some grand drama. Whether they settle on twelve, nine or fifty-three next Thursday, the telescope feeds will look precisely identical on Friday. Best let them finish the meeting first.

Punchcard · Punchcard, as of 16 Aug 2006 at 17:04 GMT

No need to apologise at all. Kev is entirely correct, and it is a pleasure to see someone look at the facts with a level head rather than jumping at shadows.

When seven people spend months attempting to solve an awkward puzzle, they rarely produce a perfect result on the first try. Gravity and shape offered them a tidy, measurable yardstick, and it is easy to understand why they seized upon it. It keeps Pluto safe for the moment, and it treats Ceres and that new body out past Neptune fairly by the same measure.

Now the rest of the assembly gets their say. Some astronomers will naturally worry about having dozens of ice balls on the list later on, while others will want a clean, round shape to remain the standard. That is simply how an open vote works. People raise their objections, they weigh the merits, and they cast their ballots next Thursday. It is quite ordinary work, and there is no need to make a mystery of it. We shall know soon enough where the numbers fall.

Walter

TheyKnow · TheyKnow, as of 16 Aug 2006 at 22:41 GMT

It is easy to call it ordinary work, my friend, but having two thousand people show up to vote on a draft that suddenly adds asteroid belts and moons was bound to cause friction... When you put up a standard that lets in dozens of ice balls overnight, you naturally invite everyone to push back against the whole thing. If the room decides that roundness alone is too messy, the compromise will end up trimming the list right back down to eight. Folks can call it standard committee business, but that still leaves Pluto right on the chopping block when the debate starts tomorrow.