Editing 2851: Messier Objects

{{comic
| number    = 2851
| date      = November 6, 2023
| title     = Messier Objects
| image     = messier_objects_2x.png
| imagesize = 293x294px
| noexpand  = true
| titletext = The debate over the correct Messier number for the Ship of Theseus is ongoing.
}}

==Explanation==
This comic is a play on the {{w|Messier object|Messier Catalog}}, which is a famous list of astronomical objects "that are not a comet" compiled by the French astronomer Charles Messier in the 18th century. The real Messier Catalog includes 110 objects, which are all deep-space objects like nebulae and galaxies. 

In the comic, it's humorously suggested that the catalog includes not just these distant celestial objects, but also very ordinary things found here on Earth. Each ordinary object is labeled with an "M" followed by a number, just as the real Messier objects are numbered (like M1, M2, etc.). However, the numbers are much higher than the 110 included in the actual catalog, and they point to mundane things such as the Earth, Charles Messier himself, a tree, a butterfly and a squirrel.

The numbers increase as the objects go from large and significant to humans (the Earth, Charles Messier) to those that are smaller and less significant (a tree, a butterfly, and a squirrel). However, this pattern isn't strictly numerical (i.e., there's no clear mathematical sequence), but rather a conceptual one where the numbers arbitrarily become larger for things that are commonly considered less monumental or noteworthy than celestial objects.

So, the comic is a playful take on a piece of astronomical history, suggesting that everything in the universe is part of the Messier Catalog, not just the deep sky objects Messier originally listed.

The title text refers to the {{w|Ship of Theseus}}. This is a popular thought experiment: if a ship is repaired and/or modified such that it has ''all'' of its parts replaced over the years, is it the same ship as the original? And then, what if you take all of the parts that were removed and create another ship using those parts? Are they ''both'' the same ship, and if not, which one ''is'' the original ship? The title text suggests that this leads to a debate as to whether the original ship and the new ship (with all of its parts replaced) should be considered the same object and therefore given the same Messier number, or the two ships should be considered different objects with different Messier numbers, and if so, which of them should retain the original number.

"M41592" may be a reference to pi as it contains 5 of the first digits at 3.1'''41592'''. Also noteworthy is that (the real) M6 is called the {{w|Butterfly Cluster}}. However, there are no real galaxies in the original Messier Catalog named after trees or squirrels.{{citation needed}}

"M137" for Earth seems likely to be a reference to the animated sci-fi/comedy show ''{{w|Rick and Morty}}'', since the version of Rick primarily followed by the show comes from Dimension C-137, even identifying himself as Rick C-137 when around Ricks and Mortys from other dimensions.

==About the Messier Catalog==
The Messier Catalog was devised as a tool for comet hunters to differentiate between permanent, blurry celestial objects and the transient, moving comets that appear similar at first glance. Such blurry objects, unlike comets, remain fixed against the stellar backdrop, and their inclusion in the catalog ensures that astronomers could avoid mistaking these for newly visible comets, when systematically looking for unfixed 'fuzzy' objects to start to track. The catalog excludes terrestrial objects, as they pose no risk of confusion with comets.{{Citation needed}} Following the creation of the Messier Catalog, other catalogs like the New General Catalogue ({{w|New General Catalogue|NGC}}) and the Sloan Digital Sky Survey ({{w|Sloan Digital Sky Survey|SDSS}}) emerged, expanding the documentation of astronomical bodies.

==Similar Numbering Systems==
This numbering system is somewhat reminiscent of Wikidata which also gives objects a number starting with a letter. Numbers starting with Q refer to concepts including specific physical objects (like the Earth) and more abstract ideas (butterflies as organisms known by a particular common name). Here are some of the objects mentioned in the comic:
:[https://www.wikidata.org/wiki/Q2 Q2] (Earth) (The normal one)
:[https://www.wikidata.org/wiki/Q14524 Q14524] (Charles Messier) (The astronomer)
:[https://www.wikidata.org/wiki/Q10884 Q10884] (tree) (The plants known by that common name)
:[https://www.wikidata.org/wiki/Q11946202 Q11946202] (butterflies) (The Lepidoptera known by that common name)
:[https://www.wikidata.org/wiki/Q9482 Q9482] (squirrel) (The taxon of rodents)
:[https://www.wikidata.org/wiki/Q14530 Q14530] (Messier object) (The astronomical catalog)
:[https://www.wikidata.org/wiki/Q1050837 Q1050837] (Ship of Theseus) (The thought experiment)
:[https://www.wikidata.org/wiki/Q13915 Q13915] (xkcd) (The webcomic)

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Multiple objects are labelled with M followed by a number.]
:[There is a tree, a butterfly, a squirrel, a man with a powdered wig labeled Charles Messier, a squirrel, and ground.]
:M137 (Earth) (pointing to the ground)
:M205 (Charles Messier) (pointing to Charles Messier)
:M21860 (pointing to a tree on the left of the panel)
:M41592 (pointing to a butterfly above Charles)
:M30712050 (pointing to a squirrel)

:[Caption below the panel:]
:People usually focus on the first 110, but the Messier Catalog actually includes '''''all''''' objects.

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Comics featuring real people]]
[[Category:Animals]]
[[Category:Squirrels]]
[[Category:Philosophy]] <!-- ship of Theseus -->