Pluto, we hardly knew you

Extract from the San Francisco Chronicle:

The recent news of the demotion of the planet Pluto to "dwarf planet" status took a lot of people by surprise. With the use of confidential sources, The Chronicle has been able to acquire the exclusive rights to the following correspondence. We feel it adds to the debate of this critical issue.

Memo: To Pluto

From: The Solar System

Subject: Demotion to dwarf planet status.

Dear Pluto:

Whew. This is a tough one. First, I just want you to know that we all feel terrible about this. I think I speak for us all -- Mars, Venus, the whole gang -- when I say you've been like a sun to us. Seriously.

Look, I can't say this is fair. It isn't. Downsizing is just a fact of life these days. It's universal. One minute you're on the "Children's Guide to the Solar System," and the next you're a black hole. Who knows how they make these calls at headquarters?

I do have to say, in all honesty, that there were some problems. A lot of it was just image stuff. We've talked about this before. Like, what makes Mercury so hot anyhow? It is hard to fight perceptions like that.

And, to be brutally honest, you probably could have done a better job with your presentation. There were times when you were seen as distant, aloof, even cold. Nobody saw you much. We ran in the same circles for years and years, but I don't think anybody really got to know you. It wasn't just your "eccentric orbit," you know. There were plenty of whispers that you were "way out there," or "too spacey."

As for the jokes, well, I don't think there was much you could do about that. "Hey look, isn't that Pluto? Out by Uranus?" How many times did we hear that one? No matter how many times we explained that Neptune is the planet next to you, it didn't matter. Sophomoric humor is a force that transcends astrophysics.

At the end of the day, I think we all realize that what it really comes down to is Earth. (I know, who made them the center of the universe?) Earth, with its big, gassy atmosphere and all those peeping pointy-headed scientists with their telescopes.

They act like they created planets. Hello? Big Bang? Ten billion years ago? Frankly, I don't get it. First they name us, then they take it away. For seventy-some years you were a planet. Now you're a "dwarf planet." What's next, changing your name to "Dopey"?

But there was a time, eh, when you were a star. Back in the 1930s, you were mysterious and theoretical. Astronomers on Earth stayed up nights thinking about you. They'd hang around the observatory, just hoping to catch a glimpse of you on a night when you were out with Neptune.

Remember the excitement when they finally saw you? There was all the talk about what your name should be. The New York Times got involved, suggesting Minerva, which sounds like a name for a new kitchen range. And then, an 11-year-old girl from England, Venetia Phair, suggested Pluto, and it stuck. (Personally, I'd say if anyone needed a new name it was Venetia Phair, but that's probably just solar snark.)

And all right, as it turned out, Pluto was probably not the most awe-inspiring choice. Jupiter gets to be the giant of the skies, and you turn out to be Mickey Mouse's dog. A bad break, no doubt about it.

Still, there was a window of opportunity there, a chance to make a name for yourself. And I'll be honest, you didn't do much to help matters. It seemed you were never available for photographs. And you projected a chilly, frigid atmosphere. It wasn't inviting, frankly.

The more they got to know you, the more there were doubts. They said you lacked "gravitas." The whisper campaign began. You were smaller than seven moons in the solar system, even -- and this was a killer -- Earth's moon.

I don't have to tell you how it all unraveled from there. There was sniping about your "oblong orbit." (Hey, we all accept the orbit we're given. It's a universal law.) A low point had to be when that big ball of ice, UB313, was put up for planethood in 2003. Hey, it's a solar system, not a Little League team. Not everybody gets to play, OK?

Yanking your planet status is a blow, no doubt about it. More than anything, I suppose, it is embarrassing. But you'll get over it. The sun will come up again in another 162 hours, just like always.

The good news is, you still have a chance to shine. Earth scientists say they are going ahead with the $700 million New Horizons spacecraft flyby. It is expected to pass you on July 14, 2015.

We're all pulling for you when that happens. We know that when they see you up close and in person they will understand that you are not some dwarf, or a "minor planet," but a key part of the solar system. We'd just say that you should always remember who you are and what we think of you.

You rock.

C.W. Nevius' column appears regularly in The Chronicle. His blog, cwnevius.blog, and podcast, "News Wrap," can be found on SFGate.com. E-mail him at cwnevius@sfchronicle.com.

Monday 28 August 2006 - 04:27AM (GMT)

Astronomical Error of Science

And so we now have a new 'scientific' definition for the word planet... Pluto get's to be called a dwarf planet. So now there are just eight classical planets and a whole load of dwarf planets most yet to be named. That's fine. No honestly, I mean it, it really is fine.

What's not fine is the definition.

Here's the IAU's two resolutions that were voted on and approved last Thursday:

RESOLUTION 5A
The IAU therefore resolves that "planets" and other bodies in our Solar System be defined into three distinct categories in the following way:

(1) A "planet"¹ is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.

(2) A "dwarf planet" is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape² , (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.

(3) All other objects³ except satellites orbiting the Sun shall be referred to collectively as "Small Solar-System Bodies".

---

¹The eight planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
²An IAU process will be established to assign borderline objects into either dwarf planet and other categories.
³These currently include most of the Solar System asteroids, most Trans-Neptunian Objects (TNOs), comets, and other small bodies.

---

IAU Resolution: Pluto

RESOLUTION 6A
The IAU further resolves:

Pluto is a "dwarf planet" by the above definition and is recognized as the prototype of a new category of trans-Neptunian objects.

Download text Word-format

It all seems ok until you read the words... " has not cleared the neighbourhood around its orbit". Scientific definitions are required to be clear, concise and objective in their statements. This to me seems not at all clear and certainly not objective. How does one interpret clearing the neighbourhood? Of what? To what extent?

I'm no astronomer and I'm no scientist. I'll admit that. But I am sure that the IAU have blundered with this defintion. Somehow, the IAU consider that the eight planets from Mercury to Uranus have all cleared the neighbourhood around their orbits. Presumably of other significant celestial objects. If they want to keep along the lines of "cleared the neighbourhood around it's orbit" then they must define this much more clearly because as it stands it is far too ambiguous.

I suppose this resolution will probably stay in place for a while. I should look on the bright side... not that Pluto has much of a bright side. Pluto has joined a new class of planets called dwarfs. He might feel more at home among friends more like himself. I look forward to getting to know the names of all his new classmates.

Here's an article from the Hindustan Times that makes a very valid point:

Which of these would you say is a dog: a German Shepherd or a Chihuahua? This is the kind of question put before delegates of the International Astronomical Union (IAU) General Assembly who powwowed in Prague over Pluto's planet-hood. No wonder hardly 300 of the 2,700 astronomers at the meet even bothered to vote for, or against, stripping the ninth rock from the Sun of its planetary status and making it a 'planet dwarf' instead.

The planets in our solar system have been traditionally divided into two main groups. The inner band of relatively small worlds - Mercury to Mars - is followed by a wide gap, where the 'minor planets' or asteroids move. Beyond this is the realm of the four giants - Jupiter, Saturn, Uranus and Neptune.

Pluto's 248-year journey around the Sun is unusual for two reasons. First, its narrow, elliptical orbit edges it closer to the Sun at times than Neptune. Second, if you imagine planetary orbits as discs and look at their edges, they will appear to lie close to each other. Pluto's disc, however, is different, being tilted at an angle of 17 degrees away from Earth's orbit.

This prompts some astronomers to suggest that Pluto is not a 'real' planet, and could even be a former moon of Neptune. With new telescope technologies enabling scientists to find more and more objects orbiting far from the Sun, some of which are similar to Pluto, the clamour for downgrading the planet has become louder.

Under the new IAU guidelines, a celestial object qualifies as a planet only if it orbits a star, without itself being a star, and is large enough for gravity to pull it into a roughly spherical shape. Besides, it must dominate its orbit, clearing away other objects. Pluto's detractors point to its highly elliptical orbit, which overlaps that of Neptune, to relegate it to a new category called 'dwarf planets'.

The problem is, this will obviously also affect Earth, Mars, Jupiter and Neptune, none of which has a clear orbital zone. Earth orbits with 10,000 near-Earth asteroids, while Jupiter's path is littered with over 100,000 'Trojan asteroids' (chunks of rubble left over from the solar system's formation more than four billion years ago).

As for Neptune, if it were to clear its zone, there would be no Pluto in the first place! Astronomers would've been better off wondering what Pluto is like, rather than what it is. For only by learning more about the outer planets can we get to know more about how the inner solar system was formed.

Planet Definition

Although there is no set scientific definition for planet (from the Greek planetes “wanderers”), as a rule of thumb, a planet: 1) must directly orbit a star or an object that has nuclear fusion; 2) must be small enough that it has not undergone internal nuclear fusion (ie, it is not a star or starlike object); and 3) must be large enough that its self-gravity gives it the general shape of a sphere.
www.infoplease.com/ipa/A0004425.html

There it's easy! One that most people can understand. So please astronomers go home or discuss something else!

Comments from Yahoo 360:

(1 total)

• Sai

okai fine, i will tell you here first

Most Voracious Energies Might Just Seem UbiQuitous

Sunday 28 January 2007 - 11:12AM (CST)