# ­xkcd thread **URL:** \ **Category:** Cafe Society\ **Tags:** comic-strips\ **Created:** [May 28, 2020, 12:57am UTC](https://boards.straightdope.com/t/xkcd-thread/854574 "2020-05-28T00:57:03Z")\ **Posts on this page:** 20\ **Page:** 204
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [March 14, 2025, 5:05pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4063 "2025-03-14T17:05:51Z")
Does today’s XKCD have an error? > **[Planet Definitions](https://xkcd.com/3063/)** Shouldn’t the graphic on the right for the second line be switch with the graphic on the right for the first line? ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [March 14, 2025, 5:15pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4064 "2025-03-14T17:15:55Z")
> [@RitterSport](#): > > Shouldn’t the graphic on the right for the second line be switch with the graphic on the right for the first line? Yes. The line “Ultratraditionalist: only the classical planets are planets” is wrong to count five planets. It should be seven. > **[Classical planet](https://en.wikipedia.org/wiki/Classical_planet)** > > A classical planet is an astronomical object that is visible to the naked eye and moves across the sky and its backdrop of fixed stars (the common stars which seem still in contrast to the planets). Visible to humans on Earth there are seven classical planets (the seven luminaries). They are from brightest to dimmest: the Sun, the Moon, Venus, Jupiter, Mars, Mercury and Saturn. > Greek astronomers such as Geminus and Ptolemy recorded these classical planets during classical antiquity, introducing ... ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [March 14, 2025, 5:42pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4065 "2025-03-14T17:42:27Z")
Please also include a large image of the strip when you post here. There’s a link to it at the bottom of the xkcd page, right below the link to the xkcd page. Right click and type L gets it copied to your clipboard, then paste it below the link here: [![](https://imgs.xkcd.com/comics/planet_definitions.png) ](https://imgs.xkcd.com/comics/planet_definitions.png) Then copy paste the title text. Right click on the strip, hit Q, Ctrl-C to copy to clipboard, paste here below the image and then clean up the cruft around the text: “Under the ‘has cleared its orbital neighborhood’ and ‘fuses hydrogen into helium’ definitions, thanks to human activities Earth technically no longer qualifies as a planet but DOES count as a star.” ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [March 15, 2025, 12:01am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4066 "2025-03-15T00:01:22Z")
I’m a heretical ultratradtionalist: we insist that Uranus is visible as a very faint and very slowly moving object, but it would have been counted as a planet if anyone could have pointed it out to ancient astronomers. The question of Vesta is still unresolved however. ---
**Author:** ![Zakalwe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zakalwe/32/270_2.png) [@Zakalwe](https://boards.straightdope.com/u/Zakalwe)\ **Post date:** [March 15, 2025, 9:58am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4067 "2025-03-15T09:58:55Z")
> [@RitterSport](#): > > Shouldn’t the graphic on the right for the second line be switch with the graphic on the right for the first line? I’m not sure I understand what you’re saying here. The first line has 9 planets in the middle column and 9 objects are colored green in the graphic. The second line has 8 planets in the middle column and 8 objects colored green. Has he fixed something you saw after he initially posted? Because it sure looks correct now. ---
**Author:** ![Ponderoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ponderoid/32/19221_2.png) [@Ponderoid](https://boards.straightdope.com/u/Ponderoid)\ **Post date:** [March 15, 2025, 11:02am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4068 "2025-03-15T11:02:32Z")
Yes, it’s been fixed. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [March 15, 2025, 11:17am UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4069 "2025-03-15T11:17:47Z")
Oh man, I should have posted a screenshot instead of a link! ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 15, 2025, 7:02pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4070 "2025-03-15T19:02:12Z")
Ref the hoverover … > [@dtilque](#): > > > “Under the ‘has cleared its orbital neighborhood’ and ‘fuses hydrogen into helium’ definitions, thanks to human activities Earth technically no longer qualifies as a planet but DOES count as a star.” I get the fusion part of his comment, but I don’t get the “has cleared orbit” part. Having natural moons doesn’t invalidate “cleared orbit”. Neither does having human-made satellites. Neither does having **[Trojans (Wikipedia)](https://en.wikipedia.org/wiki/Trojan_(celestial_body))**. So what is this proposed act of humankind which invalidates the “cleared orbit” criterion? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [March 15, 2025, 7:40pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4071 "2025-03-15T19:40:49Z")
One of my favorite little factoids is that the four Galilean moons of Jupiter are bright enough to be visible from Earth. The problem is that there are lost in the brightness of Jupiter. Munroe has seen Jupiter, and therefore has “seen” those moons. (Note that he has seen a moon of Saturn and Uranus which implies using a telescope is okay, but he’s not used one on Jupiter?) ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [March 15, 2025, 8:21pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4072 "2025-03-15T20:21:27Z")
Maybe he’s looked at Saturn through a good telescope, and has never ooked at Jupiter. 🤷‍♀️ I think I’ve seen Jupiter but not Saturn. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [March 15, 2025, 8:38pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4073 "2025-03-15T20:38:07Z")
The four Galilean moons are clearly visible with any optics of sufficient resolution to separate them from Jupiter. Even modest field glasses suffice. ---
**Author:** ![Cartooniverse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cartooniverse/32/3084_2.png) [@Cartooniverse](https://boards.straightdope.com/u/Cartooniverse)\ **Post date:** [March 15, 2025, 8:46pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4074 "2025-03-15T20:46:29Z")
> [@Alessan](#): > > > [@dtilque](#): > > > > Probably a bigger surprise is that Rutgers and Cornell are also land grant schools. > > I don’t understand. Why would that be a surprise? It surprised me. The concept seemed to apply more to states in the Midwest. Hell, I grew up in Philly and can tell you that the Pine Barrens are a vast wasteland of nothingness- perfect location to educate the next generation of New Jersians ! 😃 ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [March 15, 2025, 9:01pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4075 "2025-03-15T21:01:44Z")
And to serve as a refuge for grotesquely mutated offspring. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 15, 2025, 9:19pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4076 "2025-03-15T21:19:29Z")
Also a great landing area for Martian tripods. ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [March 15, 2025, 9:51pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4077 "2025-03-15T21:51:04Z")
> [@LSLGuy](#): > > Having natural moons doesn’t invalidate “cleared orbit”. Neither does having human-made satellites. Neither does having **[Trojans (Wikipedia)](https://en.wikipedia.org/wiki/Trojan_(celestial_body))**. > > So what is this proposed act of humankind which invalidates the “cleared orbit” criterion? I took him to mean that we’ve cluttered our orbit, but you rule that out ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [March 15, 2025, 9:54pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4078 "2025-03-15T21:54:20Z")
I think it’s called “comedic licence”. 😉 ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 15, 2025, 10:26pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4079 "2025-03-15T22:26:20Z")
> [@Lumpy](#): > > Even modest field glasses suffice. Heck, even Galileo’s telescope sufficed. Nowadays, even a Fischer-Price toy telescope probably has better optics. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [March 15, 2025, 10:33pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4080 "2025-03-15T22:33:27Z")
There’s a bunch of Apollo program debris in near-Earth heliocentric orbit. S-IVB upper stages and some spacecraft/LM adapter panels. It’s not known exactly what’s happened to it (some undoubtedly came back and impacted), aside from the stage from Apollo 12, which was identified in 2002 as J002E3. ---
**Author:** ![Zyada](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zyada/32/3028_2.png) [@Zyada](https://boards.straightdope.com/u/Zyada)\ **Post date:** [March 15, 2025, 10:58pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4081 "2025-03-15T22:58:48Z")
> [@puzzlegal](#): > > has never ooked at Jupiter. Cue up **Also sprach Zarathustra** ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 16, 2025, 4:29pm UTC](https://boards.straightdope.com/t/xkcd-thread/854574/4082 "2025-03-16T16:29:59Z")
That’s almost certainly what he meant. Stuff we threw out there that has not yet coalesced into being artificial Trojans. Where “yet” might be a very very long time. [Previous page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=203) [Next page](https://boards.straightdope.com/t/xkcd-thread/854574.md?page=205)