Talk:3063: Planet Definitions

The one currently posted has Pluto highlighted in the second box and not highlighted in the first box. Too hard to tell if it's trolling or a genuine mistake. :-D

Apparently a mistake since it's fixed now. HughNo (talk) 19:59, 14 March 2025 (UTC)

And the first one also has a moon hilighted instead I think?? 162.158.126.5 15:59, 14 March 2025 (UTC)

Was about to write the same. The coloring in the first two lines arund Pluto seem wrong (or mistankingly switched). --172.71.222.246 16:17, 14 March 2025 (UTC)

This, this is the hill I will die on. I was radicalised by this paper: Moons Are Planets: "Scientific Usefulness Versus Cultural Teleology in the Taxonomy of Planetary Science" In short; planets are what planetary scientists study. Round things with the *good stuff*: atmospheres, oceans, volcanoes (of lava or water ice) (see diagram page 53). Pluto, Titan, Ceres, Io and Europa are all in the sweet spot where you're not so small you're just a lump of rocks who happen to be stuck together into a lump, and not so large you're just a mostly undifferentiated mass of fusing hydrogen/helium plasma. And it's consistent with our pre-20th Century understanding of what a planet is, whereas the IAU definition is trying to preserve 19th Century astrology. An amazing read and a strong recommend for anyone who cares about this subject. 172.69.79.138 16:45, 14 March 2025 (UTC)

Does this sort of count as pi-related for pi day? TomtheBuilder (talk) 17:04, 14 March 2025 (UTC)

he doesn't do themed comics anymore 😔 Caliban (talk) 17:12, 14 March 2025 (UTC)

Sure he does. 2962 and 2969 weren't too long ago. Seems like it, though. 172.71.182.222 03:31, 15 March 2025 (UTC)

I don't understand either the "he doesn't do themes" bit, or the full nature of the reply, frankly. 172.68.205.122 22:52, 15 March 2025 (UTC)

I was somewhat disappointed to get to the end of the table without seeing either an astrology or Sailor Moon joke. -- Angel (talk) 18:12, 14 March 2025 (UTC)

Is it possible that Uranus is marked under "Empiricist" because of the "Randall has seen Uranus" joke? 172.70.42.178 18:38, 14 March 2025 (UTC)

The "Classical Planets" should be 7, including the Sun and the Moon.

The average distance of the orbit of the Moon around the Earth must be slightly farther away than the orbit of the Sun around the Earth, since the Moon lags behind the Sun a little more each day, but the orbits must cross or we would never have a solar eclipse :P SammyChips (talk) 19:41, 14 March 2025 (UTC)

Wouldn't the Regolithic one depend on the exact definitions of "dirt", "ice", and "covered"? It seems that an argument could be made that the giant planets also count there but have a much thicker atmosphere on the outside, and disqualifying because of the atmosphere could exclude others like Earth depending on the exact threshold used. SammyChips (talk) 19:08, 14 March 2025 (UTC)

Has Randall not seen the sun before?

I'm impressed that he has seen Uranus (unless that actually is a joke), especially if he saw it unaided (apparently it actually can be barely seen with the naked eye if the conditions are incredibly good). SammyChips (talk) 19:36, 14 March 2025 (UTC)

Could the sun be classified as a "world"? --MothWaves (talk) 19:43, 14 March 2025 (UTC)

I assumed he meant "seen directly with my eyes", so that a photograph would not count, but looking through a telescope during an astronomy night at the local University would count. And he hasn't looked *closely* at the Sun, because of the need for eye protection. JimJJewett (talk) 23:49, 14 March 2025 (UTC)

Technically, spacecraft have landed on Mercury, Jupiter, and Saturn. Just not in a survivable manner. Redacted II (talk) 19:37, 14 March 2025 (UTC)

Have we really not sent anything directly into the Sun yet? JimJJewett (talk) 23:51, 14 March 2025 (UTC)

The most "into the Sun" we've done is the Parker Solar Probe, and it hasn't attempted to 'land' there (apart from that being effectively impossible, even beyond the likes of Cassini's final fall "onto" Saturn). It's also very hard to even send things into the Sun, because the direct method would need you to send a craft from Earth backwards at the same speed as the Earth orbits forwards (or very close to that), otherwise all you can do is fall past it and loop back up again. 162.158.74.94 01:00, 15 March 2025 (UTC)

No one even knows if Jupiter and Saturn have a *land* to land on. SDSpivey (talk) 14:54, 15 March 2025 (UTC)

Sstill subject to further study, but the crushed and burnt (and probably unrecognisable) remains of the probes will be 'landed' (or floating on top of any layer that they're ultimately more buoyant than) down there, somewhere (unless they're totally ablated away, but there'll probably be some fragments of hi-tech metal frame, even if no circuit boards or metal foils survive) Should there be a form of life in existence down in the depths of the gas-giant's mass, with any curiosity to them, I imagine they'll be wondering what this new variety of 'space rain' is, that's totally unlike the usual ex-asteroidal/cometish stuff that they must occasionally get punching down through from the inaccessible upper reaches above their native environment. 162.158.74.68 19:59, 15 March 2025 (UTC)

It looks like the Pluto error in Traditionalist and Modernist images were fixed. I now see Pluto highlighted in traditionalist and Pluto unhighlighted in Modern. 172.68.7.91 19:44, 14 March 2025 (UTC)

indeed, it seems fine now, i removed my earlier comment--162.158.233.116 23:06, 14 March 2025 (UTC)

//Jean-Luc Margot wrote a serious planet definition proposal// in 2024 as a starting point for community conversations and welcomes feedback. In 2019 I wrote a small article myself on planet and moon classes simply by size. //Mondklassen "wwwahnsinn"// (in German). 162.158.159.108 19:49, 14 March 2025 (UTC)

I'm disputing that there has never been a formal definition of "planet" prior to 2006 - the ancient Greek definition of "wandering [relative to seemingly-fixed stars] points of light in the night sky" seems formal enough to me. I marked it {{actual citation needed}}. 198.41.227.73 19:52, 14 March 2025‎

I've reworded the sentence to say "in modern times" so we aren't making unfounded and likely-incorrect claims about antiquity. 198.41.227.73 21:19, 14 March 2025 (UTC)

Does anyone else strongly dislike the term natural satellite replacing moon? Under the new nomenclature, only Earth's moon is 'the Moon'. All other moons are now merely natural satellites. Phobos, Deimos, Ganymede, are no longer considered moons. My biggest problem with the new definition is that planets themselves are natural satellites of stars. 172.71.182.225 20:13, 14 March 2025 (UTC)

It seems likely that the Saturnian moon highlighted in the Maritime definition is Titan, since it has liquid seas and lakes on its surface. 172.69.6.5 21:54, 14 March 2025 (UTC)

I've noted in the Transcript that (despite apparently being identical pre-highlight drawings in all other ways, or at least very consistently reproduced), Saturn is given one moon most of the time, but two moons on occasion. Similarly, Uranus's moons (spread from upper-right to lower-left) do-or-do-not include the dot (in one case suffering a highlighting) moving across the face of the planet. From an analytical perspective, I'm wondering if Randall did indeed copypaste the 'normal' iillustration, but then have to manually add in "whoops, I forgot I need to highlight a further item thaat I haven't already drawn" into some of the established copies, touching up where necessary (and maybe where still not necessary too). ...But I'm not sure it matters what he did or did not do. It's just an observation about the result. 172.69.79.190 23:03, 14 March 2025 (UTC)

Yeah, Titan's present in all the diagrams, and a second moon of Saturn shows up when highlighting is necessary. The bonus "Marine Biologist" planet is clearly Enceladus, but the bonus "Judgemental" planet doesn't line up with it: presumably it's one of Saturn's other moons. Which one? My wild guess is Iapetus. 172.68.150.27 01:48, 15 March 2025 (UTC)

Great explanation, thank you, but was it really necessary to include a snide dig at Baby Boomers? Not a BB myself - I'm gen X, if we're using those facile labels - but surely we don't need to encourage intergenerational resentment and conflict. 172.68.174.116 03:22, 15 March 2025 (UTC)
As a historian, I strongly disagree with the snide definition of tradition. (No, not a BB.) 162.158.212.132 07:40, 15 March 2025 (UTC)

That's a direct quote from a prior comic, that whoever wrote it in the first placce ysed, so I've rewritten it to perhaps not look quite so much like some editor's own grudge/snidiness (which it may or may not be, but not without Randall giving justifiable precedent to say it). Maybe can be tweaked further, but it might be a shame to lose the inter-comic referential humour that (regardless of tone) is staple for this site. 162.158.74.109 12:25, 15 March 2025 (UTC)

I wrote it. No snideness intended. I thought the connection was topical. Unfortunately, thanks to the "Okay boomer" phenomenon, any reference to the generation comes across as condescending. The "Tradition" strip was published in 2011, and the phrase rose to popularity in 2019. It, like 36, is just one of those things that is not standing the test of time. 172.70.47.89 20:22, 15 March 2025 (UTC)

I believe we're currently missing part of the joke in the mouseover text. Not only is Earth now a star because of human fusion, it's also no longer a planet, because, due to human satellites and spacecraft, it no longer clears its orbit. 198.41.227.42 06:20, 15 March 2025 (UTC)

Isn't the usual singular of criteria criterion? According to my dictionary, a criterium is a type of cycling race.--172.71.26.100 09:46, 15 March 2025 (UTC)

Indeed. Maybe a thinko, though, rather. 172.69.79.139 11:06, 15 March 2025 (UTC)

I am curious why only one of the Galilean moons counts as pretty, and I wonder which one (either Ganymede or Callisto, given where its drawn). They are all pretty to me, I like how surprisingly distinct they look from one another. Terdragontra (talk) 13:18, 15 March 2025 (UTC)

Re title text: With the launch of the JWST, Earth has no longer cleared its orbital neighborhood, right? 172.70.176.57 14:27, 15 March 2025 (UTC)

I tend to go by an expansive definition myself, considering all dwarf planets "planets" in my eyes. But I'm not like, arguing with the IAU's definition, this is just how I prefer to think of them, because dwarf planets are really cool. 172.70.126.140 19:35, 15 March 2025 (UTC)

In the title text explanation, there's no mention of the inclusion of the phrase about Earth clearing its orbital neighborhood. I think this has something to do with all of our man-made satellites that have not been cleared from Earth's orbital neighborhood. Does anyone else think that's an important part of the title text and needs to be explained? Ianrbibtitlht (talk) 13:33, 16 March 2025 (UTC)

I think I like the "Recognizable" criteria. Something is a planet if it orbits the Sun and there exists at least one photograph of the object that a reasonably knowledgeable layperson can correctly identify. That would mean that all of the IAU defined planets are planets (except maybe Mercury), and that Pluto became a planet in 2015. 172.68.245.141 14:34, 16 March 2025 (UTC)

...there's a risk that Uranus and/or Neptune ("or both... hang on... which one's supposed to be bluer..? and is this one of those miscalibrated images or not..?") might drop out of the Recognisable grouping. And the Moon would be added, unless you arbitrarily banned near-side images, in which case it'd be demoted to "dunno" except by particularly adept selenophiles who probably even know the far-side, and limbs, like the back of their own hands. 162.158.74.94 16:55, 16 March 2025 (UTC)

A definition I thought up a while ago that I'm pretty proud of is that a planet is an object that is not a star or moon, has a stable orbit around a star, and that has a larger mass than the largest moon in its solar system. (a moon is defined as having a barycenter inside an object that directly orbits the Sun). That way, there is a clear, natural, distinction of larger bodies and smaller ones that conforms to the public thinking of a planet as large and not a moon. By my definition, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. (Though Mercury is famously smaller in radius than the moons Ganymede and Titan, it has more mass -- and given that mass grants greater gravity, I consider mass to be more important). My wider category of a world is for all star-orbiters that have differentiated layers, so the worlds in the Solar System would be (I think) Mercury, Venus, Earth, the Moon, Ceres, Vesta, Jupiter, Ganymede, Callisto, Europa, Io, Saturn, Titan, Uranus, Neptune, Triton, Pluto, Charon, Quaoar, Haumea, Makemake, Gonggong, Eris, and Sedna. This would be a harder category to assign than planet and a bit more fuzzy -- which plays in to the fuzzy use of world already existing -- but is still more clear cut than "gravitationally rounded" as no object is a perfect sphere and the strict definition of hydrostatic equilibrium means Mercury is not a planet. Of course, since no exomoons have been discovered as they are very hard to find, all exoplanets discovered would be planets -- which is nice and uncomplicated and natural for the human to assume that the bodies are planets. 108.162.245.145 18:11, 16 March 2025 (UTC)

"Modern" vs "Current". Does anyone feel frustrated when people confuse "modern", "contemporary", and "current"? "Modern" is post-1500, "contemporary" is the age someone lives in, and "current" is 'today'. Throughout 75 years of the modern era, Pluto 'was' considered a planet. Is anyone willing to shift non-canonical usage of "modern" to "current" in the article? 172.71.95.28 15:59, 15 March 2025 (UTC)

"Modern" is post-1500" -- Museum of Modern Art, 1929/1930 until today (essentially Pluto's reign); works to 1885 --PRR (talk) 00:54, 17 March 2025 (UTC)

Citations

I added a bunch of Wikipedia citations. I went by the WP rule (citation needed) of linking the first non-parenthesized instance of a word/phrase. That does make for some awkward things, like lists with only some of the items linked, and the moon link in a mention under Simplistic rather than on the more relevant Lunar. –P₁h₃r₁e₃d₁₃ (talk) 22:34, 14 March 2025 (UTC)

Round vs Spheroidal According to the "simplistic" definition, the rings themselves (also round) are separate planets. If the simplistic definition had merely been "spheroidal" rather than "round", they would not be. I'd love to see a version of the chart where Saturn is green, but the rings are white. 172.71.99.166 23:36, 14 March 2025 (UTC)