Comments on Mike Brown's Planets: Planetary Placemats

Pluto was a planet for what? 50 years? That's ...

2011-08-09T11:33:05.551-07:00

Pluto was a planet for what? 50 years? That's really not a long time in the solar system, or even the historical, scheme. Ceres was a planet for a couple decades, too. Bet you don't miss it, just because its time as a planet was before you were alive. Kids learning the solar system without Pluto will do just fine without it.

I've always considered Pluto a proper and dign...

2011-06-20T01:18:35.170-07:00

I've always considered Pluto a proper and dignified planet. The IAU should have grandfathered it in to the current list. I grew up studying the 9-planets quite a bit in primary school.

On the rainy days we'd be home from school, my buddies and I would study the Solar System in great detail and if we got lucky, the evening would clear and we could play with our Edmund Scientific telescopes in the evening. I remember BS-ing the whole neighborhood that I could find Uranus and Neptune. But all I really did was defocus a bright star!

If the weather stayed bad, we'd play Saturn Navigator on the Apple II+ computer we had. Or perhaps use The Planetary Guide. Well, today it is Stellarium and Orbiter on a modern PC.

Anyways, back to Pluto - it's been a planet so long why change it now? It's not like it's "bad science" or anything, just a categorization, that's all. There's plenty of other objects in the Solar System to put into categories without having to steal Pluto and place it there.

It's like an old friend. And the Solar System seems incomplete without it.

I bought this placemat at WalMart a couple years a...

2010-12-06T07:45:32.256-08:00

I bought this placemat at WalMart a couple years ago. It's a lot better than the first version they had. I have several mats, including the US Presidents and a US Map tucked away at home. I started bringing them to my Girl Scout meetings and throwing them out on the Art Room tables before the girls arrived.

The solar system is not a subject I've had to force on them. The handbooks only do moon phases, but I had the girls checking spaceweather.com and playing Magnetosphere Tag by third grade. Last week I bumped them up to the Transit of Venus and the Venus pentagram while playing with Spirographs.

I've had no hesitation in showing them a horoscope with the current transits on it either. It is the quickest way to explain orbiting position and speed. They grasp 'where' they are in a different way then most kids.

Kaden

Hi Mike, I am really surprised by the relative siz...

2010-12-06T01:17:29.663-08:00

Hi Mike, I am really surprised by the relative size of our planets and also by the emptiness of our solar system. It seems that what we have been taught and belived about solar system really needs rectifications. I am very much interested in astronomy and visit nasa websites and keep track of astronomy news through google. Thanks for the info on this blog. I already bookmarked this page...thanks a ton

Well Dr Mike Brown is certainly the "Dan Brow...

2009-12-18T01:04:48.026-08:00

Well Dr Mike Brown is certainly the "Dan Brown" on writing exciting stuff on the objects at the cold & dark edge of our Solar system...
Phill
Belgium

Mike, love the final planetary placemat. I'd ...

2009-10-22T16:18:49.451-07:00

Mike, love the final planetary placemat. I'd buy several of those. Matt, we had a planet walk like that set up in DC for a while. I loved the idea, but the walk grew quite long near the outer reaches of the solar system (although I guess that was the point!). Simeon, feel free to drop by any time and paint the ceiling of my sons' bedroom. I know they'd appreciate it. ;)

hey mike, i hope you don't mind my saving your...

2009-10-21T07:34:16.240-07:00

hey mike, i hope you don't mind my saving your final placemat image to my desktop; i'm thinking of tweaking the colors and using it for my desktop background =)

i haven't been able to get the idea of it out of my head since i first read this post so...i figured i'd come back

Oh My God, this is perfect! As a elementary teach...

2009-09-20T13:40:34.147-07:00

Oh My God, this is perfect! As a elementary teacher, I am constantly battling small children's ideas, as well as other adults (teachers, no less) in giving up the idea of pluto as a separate planet. I love showing all the other TNO/KBOs and asteroids on my planetary wall! Now the placemat idea #3 is perfect for me to show my students! I think this might actually help some adults get the right idea! Thank you! Thank You! from science teachers eveywhere!

It occurred to me that you can show relative sizes...

2009-09-16T16:59:28.055-07:00

It occurred to me that you can show relative sizes and distances without making a linear map. A joke example is the New York-centric map where
distances scale negative-exponentially with distance from NY.
After some experiments, I decided a power function preserved information better.

http://openaccess.org/~flipandzeke/zeke/images/SoSyMap34.pdf

maps the Solar System with both diameters and semimajor axes scaled as a 3/4 power.

May I make a couple of quick suggestion for your p...

2009-09-16T03:59:03.536-07:00

May I make a couple of quick suggestion for your placemat? You could restore the relative distances by scaling the x-axis just as you did in your first attempt, but keep the planet scales the same as in your last.

Draw vertical lines down the paper showing the orbital distances of all of the bodies which are primarily orbiting the sun. Each planet would then be drawn horizontally centered on it's orbit line (vertically placed to be ascetically pleasing). For planets with high eccentricities, the orbit line could be two-toned. A light color bar displaying the full width of the orbit, and a darker color for the mean orbital distance.

The moons could also be restored on this map by rendering them on small circles, with similar distance and size scales.

Mike, This isn't a placemat, but the ceiling ...

2009-09-01T07:38:29.042-07:00

Mike,

This isn't a placemat, but the ceiling of my daughter's room. I did this about 6 months ago when she started getting interested in learning about "outer space" (she's 5).

I put all of the planets, the larger moons, plus the dwarf planets and named TNOs. The sizes are correctly scaled, and the distances from the sun are correctly scaled (of course not on the same scale as the sizes).

Everything from the Sun to Saturn (you can see Ceres and some asteroids if you squint)

Looking towards the outer solar system (the named TNOs are there after Neptune, but I don't have a good picture uploaded that shows them well).

I thought you might like it.

Mike: I realize you've got lots of other thing...

2009-08-31T19:22:54.541-07:00

Mike: I realize you've got lots of other things on your mind right now (like the fate of astronomical landmarks) ... but all the hubbub put me in a mind to check back and see that you answered my post. No, I don't think you (or nature, for that matter) are limiting the list to eight. In fact, I like the fact that even on the scaled-down version of the placemat, I can squint my eyes and see Ceres and about eight of the Kuiper Belt objects as definitely distinct, not all that much smaller than Mercury. (Eris is about half the width of Mercury, the next planet up ... while Earth is about a quarter the width of Neptune, the next planet up.)

I also like the fact that there are all those other spots on the mat. That's just as it should be. I worry that by artificially limiting the list to eight (or perhaps four, if a Neptunian was in charge of the job), folks limit their view of the solar system when it actually should be widened.

@Tom: Yes, I get excited about Uranu...

2009-08-29T06:10:45.062-07:00

@Tom: Yes, I get excited about Uranus and Neptune! (Especially Uranus!)

I'd LOVE to see a mission like Cassini to each of those big planets, as I expect that they could discover lots of interesting stuff out there.

@Mike Brown: Thanks for this article! I never really thought about that when looking at depictions of our solar system. Of course I knew that Pluto was much, much smaller than usually depicted, but I never fully realised to what extent. I'd definitely buy that placemat for my little nephew (or even for myself). And I quite like the colours of your "theoretical placemat", I'd even buy it like that, without names or "artistic renderings" on it!! ;-)

Firstly, I agree with previous commentators that a...

2009-08-28T17:31:10.387-07:00

Firstly, I agree with previous commentators that any depiction showing objects smaller than Mars needs to show moons as well.

Moons are interesting. After all, how many of your research-related posts this year have been about satellites of one body or another?

Secondly, you've inspired me to a more general comment on astronomical definitions:
http://lablemminglounge.blogspot.com/2009/08/new-definitions-from-international.html

Whoops that was me talking about exo and ino plane...

2009-08-28T06:37:08.121-07:00

Whoops that was me talking about exo and ino planets.

Our Solar Systemcentric definitions for exoplanets...

2009-08-28T06:35:34.624-07:00

Our Solar Systemcentric definitions for exoplanets would have been better not made but everyone was expecting one defintion offered by the IAU for both exo and ino (yeah I just coined another word candidate) planets.

This hang-up on size perplexes me. A dust mite an...

2009-08-27T08:39:37.801-07:00

This hang-up on size perplexes me. A dust mite and an apatosaur have an enormous size differential, yet both are recognized by biologists as animals. What biologist would deny that anything smaller than a hummingbird cannot be labeled an animal simply because it is too small? Or that a dust mite doesn’t “deserve” the label of animal because it isn’t as big or “important” as a brontosaur? Or that a line must be drawn somewhere because otherwise there would be too many animals? Sorry, but the logic totally escapes me.

Also, I wonder how these planet definitions will possibly survive future observations. As planet detection around other stars improves, it seems quite possible, even probable, that astronomers will find at least one Earth-size or larger body that has not cleared its orbit of debris. And what will happen if astronomers get really good at finding stuff and detected some small, icy body orbiting a red dwarf all by its lonesome? For that matter, what happens when we find some Jupiter-sized body wandering between star systems? I guess we’ll call it a “rogue planet?” So then we’ll have rogue planets, dwarf planets, ghost planets, evil planets, etc., but none of these will “really” be planets? Aye aye aye! My head is spinning like a neutron star!

The IAU never had the power to demote or promote a...

2009-08-27T02:04:19.063-07:00

The IAU never had the power to demote or promote anything. It is a matter of language. If enough people call Pluto a planet it is. A segment calls it a planet and a segment doesn't. You can't rewrite old usage so that suddenly it is wrong. I invented the slowly catching on word Exodwarf and wrote an article about Planet definition on my blog that I am fixing to allow comments. http://www.oneworldblueportals.com/bernardsstar/index.php?page=blog

So how can we get one of these placemats? Who eve...

2009-08-26T20:48:25.284-07:00

So how can we get one of these placemats? Who even makes the things?

--Greg

I'd like to see a planetary placemats of other...

2009-08-26T17:12:49.472-07:00

I'd like to see a planetary placemats of other star systems. Would the IAU definition of a planet still stick?

If you grew up with a placemat like this, or a ...

2009-08-26T02:05:13.540-07:00
If you grew up with a placemat like this, or a wall poster in your third grade classroom, or a lunch box you carried every day, I now understand why you feel Pluto still deserves to be a planet.

This makes a lot of sense when understanding the reactions of taxi-drivers who implore scientists to 'reinstate Pluto'. It's less convincing (at least by itself) when trying to understand why tenured Professors of Planetary Science get so hot under the collar. I have my own theories ('IAU rules geology still more boring than astronomy' - Prague, 2006) but I'd like to hear what other people think.

Alan - wait wait wait wait! Did you look at the pi...

2009-08-25T20:19:32.478-07:00
Alan - wait wait wait wait! Did you look at the pictures? Everything orbiting the sun that is big enough to appear as large as one pixel across is there, with no human-made distinction. The only distinction is the real one between the 4 really big things, the 4 moderately big things, and all of the small things. It's not me limiting the planetary tribe to 8, it's just nature!

By the way, if length were no object in the placem...

2009-08-25T16:14:52.726-07:00
By the way, if length were no object in the placemat, I'd definitely roll this one out:

http://www.kokogiak.com/gedankengang/2007/03/all-known-bodies-in-solar-system.html

I like the idea of planetary placemats, but I thin...

2009-08-25T16:12:29.960-07:00
I like the idea of planetary placemats, but I think it would be a terrible misrepresentation to leave the asteroid belt and the Kuiper Belt objects off the mat ... almost as bad as making Pluto bigger than Mercury. That's the problem with trying to limit the planetary tribe to eight, in my humble opinion: You lose the sense of diversity in the solar system. I can imagine that even Lila (or other kids) would feel let down if they didn't see that little string of pearls in the lower right. Whether you call them the pearl planets, or dwarf planets, or ice worlds, or KBOs (which is about the least evocative label you can put on a planetary pigeonhole), I'd have to insist that "the kids stay in the picture," to paraphrase Darryl F. Zanuck.

Your post has sparked all manner of interesting th...

2009-08-25T09:24:09.492-07:00
Your post has sparked all manner of interesting thoughts, Mike, and I could probably write three or four terrifyingly large comments about different issues you've raised. Unfortunately, that might run me afoul of my rather own liberal rules on procrastination control. So I'm going to pick one.

I think one of the big reasons that Plutophiles are so attached to planethood stems from how pretty much every elementary school student comes to learn about the solar system: we think of it as a collection of planets, no more, no less.

It starts on places like Lilah's placemat and posters and lunchboxes. But open up any fourth grade science textbook--be that one from the 1950s or 1990s--and you'll see that their chapters on astronomy are laid out in pretty much the same way. You get a quick mention of the sun (if you're lucky), then consecutive sections starting with Mercury and ending with Pluto. Each kid is expected to learn one or two basic characteristics about each planet (ie, Mars = red; Jupiter = big; Saturn = rings) and learn their order from the sun. This basic arrangement of facts is repeated whenever, say, the Magic School Bus takes a trip through the solar system.

By virtue of the fact they suffer the indignity of orbiting around another world rather than the Sun, bodies like Io and Europa and Titan basically vanish altogether from a childs-eye-view solar system. Yes, those moons might eventually appear briefly in their parent planet's section in the book in seventh grade, but by then the picture is kind of set. Indeed, even our own moon gets pretty limited play in introductory astronomy, at least in the context of being a "member" of the "solar system."

But the childs-eye solar system IS the solar system of pretty much all non-astronomers. That's not to say the educated layman didn't get quite intrigued when Huygens took its plunge, but rather that this Titan place was a sort of late paste-on onto the initial mental map they had of a nine-planet solar system.

For my money, though, the Titans and Europas are far more interesting worlds to tell a nine-year-old or a ninety-year-old about than, say, Uranus and Neptune. (Aside: Does anyone anywhere ever really end up getting particularly excited by Uranus and Neptune? Oh look, the tippy-over planet that sounds dirty. Oh look, that other, um, blue one. Even in the big leagues, are there any passionate researchers out there who've devoted their lives to Neptune?)

For lack of a better term, there was a "planet-ist" bias at play when we were all taught what the solar system was. No wonder, then, that when Pluto was reclassified there were various irksome lines in the press about it getting "kicked out" or "dropped from the Solar System."

Bound up in Pluto's planethood is this fear that if it isn't in the same club as the other eight it simply won't count anymore.

It's silly, but in a world where most educated people's mental pictures of the solar system look like those placemats, it's somewhat valid. I guess the real question is what to do about it.

Yes, the eight planets will always enjoy a certain sense of top-of-mind prestige, but we really need to do more to ensure that non-planet members of the solar system get the shrift they deserve when kids learn about the solar system in the years to come. We can't expect Lilah and her schoolmates to be running around the playground rattling off some sort of Ceres-Vesta-Pallas-Hygieia singsong bit, but it would be cool if they learned about volcanoes on Io the same time they learned about gigantic cyclones on Jupiter.