13
$\begingroup$

We seem to have named every moon orbiting other planets. Why haven't we named our own moon? And for that matter, why doesn't our sun have a name since we name or number stars?

$\endgroup$
  • 1
    $\begingroup$ I get the confusion for the moon, as there are many celestial objects which are called moons, so "The Moon" may not seem like a name. But there is only one Sun - it's a completely unique identifier for our star. What would suggest that this commonly used, unique identifier is not a name? $\endgroup$ – Nuclear Hoagie Nov 30 '20 at 16:26
  • 5
    $\begingroup$ Related in Space Exploration SE: Does the moon have a name? As shown in this answer NASA sometimes uses "Luna" as a backup name for Earth's natural satellite. $\endgroup$ – uhoh Nov 30 '20 at 23:19
  • 1
    $\begingroup$ What is "Earth's star" supposed to mean? That title edit didn't made the question far more confusing. The grammatically correct version by Glorfinel was clearer. I'm rolling back $\endgroup$ – James K Dec 1 '20 at 23:27
  • 1
    $\begingroup$ This question is prima facie evidence that the ordering of answers needs to be changed. The accepted answer is wrong. $\endgroup$ – David Hammen Dec 2 '20 at 13:06
  • 1
    $\begingroup$ This question ignores the reality that for 99.99% of humanity's existence, there was only one sun and only one moon: The Sun and The Moon. $\endgroup$ – RonJohn Dec 3 '20 at 18:42
6
$\begingroup$

"The Sun" is fine as long as you're not leaving our solar system; less so "the Moon" when there are hundreds of planetary satellites in this system alone.

In science fiction as varied as Isaac Asimov and ''Star Trek'', the names are Sol and Luna.

EDIT: My point is that sci-fi authors are writing from the point of view of societies with many "suns" and "moons", and those societies have adopted the classical terms as the "current" official names.

$\endgroup$
  • 3
    $\begingroup$ @anoe Sol is also Latin for Sun. $\endgroup$ – Toivo Säwén Dec 2 '20 at 12:52
  • 16
    $\begingroup$ This should not be the accepted answer. $\endgroup$ – David Hammen Dec 2 '20 at 13:00
  • 2
    $\begingroup$ "The Moon" is also fine if you don't leave Earth, which is a valid assumption for the vast majority of people using the term. $\endgroup$ – chepner Dec 2 '20 at 19:16
  • 3
    $\begingroup$ Strictly speaking, "sól" is the Old Norse word, and "sol" is the Latin word. The two are cognates, both coming from the same Indo-European root that also means "sun". $\endgroup$ – chepner Dec 2 '20 at 19:19
  • 1
    $\begingroup$ @DavidHammen I'm a little surprised myself. $\endgroup$ – Shawn V. Wilson Dec 3 '20 at 4:55
59
$\begingroup$

What is a name?

A name is a word, that is reasonably unique, that is used to identify a person or thing. When a child is born there is no word that identifies it, and so its parents have to choose a "name". Similarly when a new astronomical object, such as an asteroid, is discovered, it has no word that identifies it and so it is assigned first a number and later a name.

But there is already a word that identifies our sun and moon: "the Sun" and "the Moon". There is no need for a new name because they already have a name. Notice that English (unlike some other languages) gives us a typographical clue that these are names, because the first letter is capitalised. The Moon is a moon of the Earth and the Earth is a planet orbiting the Sun.

Earth, Moon and Sun are the correct names in English.

$\endgroup$
  • 20
    $\begingroup$ We will rule over all this land! And we will call it… this land! (Firefly TV series) $\endgroup$ – IMil Nov 30 '20 at 23:56
  • 5
    $\begingroup$ "What is a name?" Cue the Vsauce music ;) $\endgroup$ – Nilay Ghosh Dec 1 '20 at 3:45
  • 2
    $\begingroup$ This is similar to the distinction between "God" and "a god", the former being the sole creator of the Universe as described by monotheistic religions, while the latter is one of many superpowered entities in polytheistic religions. $\endgroup$ – vsz Dec 1 '20 at 10:35
  • 8
    $\begingroup$ @Hobbamok: Just hope the name for The Earth doesn't become "Old Earth" - that's usually a bad sign. $\endgroup$ – Peter Cordes Dec 1 '20 at 10:48
  • 4
    $\begingroup$ @PeterCordes The Earth will probably stay "The Earth" while the newly colonized world will be "New Earth" instead ;) $\endgroup$ – Rafalon Dec 1 '20 at 12:31
26
$\begingroup$

Of course the Sun and the Moon have names. The names of those objects in English are "the Sun" and "the Moon". Note the use of a definite article ("the") and the capitalization of the names themselves to indicate a proper name. The Sun and the Moon have many names, at least one name for each for almost every language ever spoken. The translations of those myriad names into English are inevitably "the Sun" and "the Moon". Being the two most obvious celestial objects, those names have been around for a long, long time, almost certainly predating writing.

On the other hand, the knowledge that the Earth is a planet that orbits the Sun is rather new, less than 500 years old. The knowledge that other planets have moons is newer yet, about 400 years old. The knowledge that the Sun is a star is even newer, less than 200 years old. Giordano Bruno was burnt at the stake in 1600 for suggesting that the Sun is a star. It wasn't until the 1830s when scientists were able to measure the enormous distance to even the closest stars.

$\endgroup$
  • 20
    $\begingroup$ Giordano Bruno's views on the nature of the sun were only a very minor part (and possibly no part at all) in why he was burned. Denying that Christ was divine was the biggest bit. $\endgroup$ – Valorum Dec 1 '20 at 0:32
  • 1
    $\begingroup$ @Valorum Or even real, as Giordano Bruno was a docetist as well as a pantheist. Pretty heretical. $\endgroup$ – Cees Timmerman Dec 3 '20 at 3:06
22
$\begingroup$

It is named 'Sol' and the moon was named 'Luna'. Hence the term Lunar explorer and 'Solar' System..

Other cultures have used different names for our Sun and Moon (for thousands of years) - So actually they have multiple names each.

Most people refer to them simply as "The Sun" & "The Moon".

$\endgroup$
  • 4
    $\begingroup$ Isn't "Sol" just Spanish for "sun" and "Luna" Spanish for "moon"? $\endgroup$ – Bookaholic Dec 1 '20 at 10:13
  • 23
    $\begingroup$ @Bookaholic: The words are originally Latin, and they are sometimes used when you want something distinct from the common words in your own language. $\endgroup$ – Michael Borgwardt Dec 1 '20 at 10:42
  • 5
    $\begingroup$ @DarthFennec: from a Spanish speaker, there is (almost, I guess?) never confusion. "El sol" is completely different from "un sol" (exactly like "the sun", "a sun" in English). Same with "la luna" or "una luna". They are never used without articles. $\endgroup$ – Martin Argerami Dec 1 '20 at 18:59
  • 5
    $\begingroup$ The first sentence of this answer is flatly incorrect for english speakers. "Sol" and "Luna" are commonly used in science fiction, but not as official terminology. $\endgroup$ – Harabeck Dec 1 '20 at 19:20
  • 8
    $\begingroup$ @Harabeck it's always risky to speak for everyone! You'll have to inform NASA that they are not English speakers, and while you're at it, that English is no longer capitalized? $\endgroup$ – uhoh Dec 1 '20 at 23:27
6
$\begingroup$

Well, even though one may encounter some "poetic" names such as Sol or Luna, I believe these bodies are referred to as "the Sun" and "the Moon", and that is the only formal name I've heard of.
As for the reason, I'd say it's because there is no need for special names like Sol because they aren't really used in practice (we've known of the Sun and the Moon for quite a bit), while it is quite important to name newly discovered objects so we would know what to refer to them as.

$\endgroup$
  • 2
    $\begingroup$ Other poetic names for moon: Selene, Cynthia $\endgroup$ – Nilay Ghosh Nov 30 '20 at 12:42
  • 19
    $\begingroup$ Note that "Sol" and "Luna" are Latin for "Sun" and "Moon". $\endgroup$ – David Hammen Nov 30 '20 at 13:39
  • 5
    $\begingroup$ Less poetic but more official: Earth I planetarynames.wr.usgs.gov/Page/Planets#EarthSystem $\endgroup$ – Jean-Marie Prival Nov 30 '20 at 15:45
  • 1
    $\begingroup$ @DavidHammen and in Spanish, too $\endgroup$ – Aaron F Nov 30 '20 at 16:04
  • 1
    $\begingroup$ And Luna is in Russian as well :-) $\endgroup$ – Tosic Nov 30 '20 at 17:30
4
$\begingroup$

I did not find any definite reference, but if the Sun and the Moon had any other official name, it would have come from the International Astronomical Union (IAU). The only reference I found was a mention in passing of Sun and Moon (capitalized). https://www.iau.org/public/themes/naming/ There may be more information hiding in some publications. But if they had another official name for these two celestial bodies, it would seem reasonable to expect that it would be featured fairly prominently on their Web site.

It would in fact make some sense to have distinctive names, to avoid statements like "Alpha Centauri is the sun of another planetary system" where sun does not refer to our Sun. That may have been the idea behind the notion that there is a distinction between "Sun" and "Sol". But it does not look like the IAU backs this up.

As best as I can tell, that idea may have originated in Hollywood, specifically Star Trek. Since I do not have any definite information to back that up, take that with a grain of salt.

$\endgroup$
  • $\begingroup$ Sol and Luna are Latin. Like plants, animals, and planets, it makes sense to use a dead language with simple characters as a global scientific standard in place of many localized names. $\endgroup$ – Cees Timmerman Dec 3 '20 at 2:57
2
$\begingroup$

Because there's no need to. "Sun" and "Moon" are relative terms and it's clear which bodies we mean (as long as we say the Sun / the Moon) when on Earth. If you stood on Proxima b's surface, Proxima Centauri would be your Sun, Proxima b's spherical satellite (if it has one) would be your Moon, and the Earth's Sun would be an average star in the night sky we'd have to find a name for in such case (e.g. Cassiopeia VI since it would enlarge the constellation of Cassiopeia by another star). But as long as you're on Earth, it doesn't matter.

You can even use the term "Earth" relative for another planet you're on in the sense of "land", just like we talk about a "geology of Mars" (geos is Greek for 'Earth').

$\endgroup$
  • 2
    $\begingroup$ Presumably if we start living on other planets and travelling between their moons becomes more commonplace, calling our moon 'The Moon' might actually start to be problematic. Especially when discussing things in the frame of reference outside of any particular planetary system. $\endgroup$ – JeffUK Dec 1 '20 at 11:23
  • $\begingroup$ @JeffUK It's just in case a planet has exactly one spherical satellite. If the planet's inhabitants aren't capable of interplanetary spaceflight, they would call it simply 'the Moon'. $\endgroup$ – Greenhorn Dec 1 '20 at 11:25
1
$\begingroup$

There isn't a general naming scheme. However, we can leverage a pattern for naming the apsis of orbits. We historically named these on a per-host body basis, so apogee and perigee were the names for the furthest and closest an orbit gets to the Earth, respectively. The -gee suffix is derived from Gaia, so that would be the name for our planet. The solar apsis are apohelion and perihelion, the -helion suffix being derived from "Helios," the Greek god of the sun. Lunar apsis have used -lune, -cynthion and -selene, deriving from names Luna, Cynthia, and Selene.

These are, of course, just one of many names that could be used, but the pattern of using historical gods would have value in such a situation. We might talk of a "new Earth" or a "new Sun" to describe a planet or a star that is similar in characteristics to our planet or star, so those names might shift from nouns to adjectives, describing planets or stars. However, there is little reason for a historical deity to be associated with a celestial body that was never seen by that historical society. It is unlikely names like Luna or Helios would ever be applied to bodies outside our solar system. Whether they would get applied to bodies in our solar system is a question for the linguists. It would depend highly on how we adapt other words like "sun" and "sol" in a multi-solar-system society.

And that linguistic adaptive approach would answer your question as to why we don't have names for them. Currently "sun" is sufficiently descriptive that it acts like a noun in our speech and needs no additional context. "The moon," with the pronoun "the" included is sufficiently descriptive. For the ancient Greeks, there wasn't even a need to identify the Earth's moon from a moon of Jupiter, because they didn't know Jupiter had moons.

For all I know, we'll name "the Sun" "Sun_00001" to disambiguate. But there does seem to be a history of leveraging the ancient deities when disambiguation is needed in a language.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.