Here is my take on the classification system. Etymologies of words in English have always interested in me, so hopefully I can be of use to you. NOTE: I DON'T SPEAK ANY OTHER LANGUAGES, so I am not aware of any translation issues. Most of this is from Google, Wikipedia, or Dictionary.com
Bulk: terra - aquaria - carbonia - ferria - neptune - jupiter - chthonia - asteroid
I was thinking that terra could be changed to something like terrestrial or telluric, but as said before, it would change the parallel syntax that should be maintained in the classification system (adjective classes describing the noun bulk). Either way, both terrestrial and telluric are derived from Latin words for Earth (Terra
). The aquaria class technically could also be called panthalassia (derived from the name of the superocean Panthalassa c. 250 Ma; the word itself is Greek and literally translates to "all ocean") but aquaria is definitely simpler and easier to understand/recognize for most people. There's nothing wrong with carbonia or ferria, as they are both derived from their Latin roots (carbo
, coal; ferrum
, iron). Neptune and jupiter are tricky! There is no widespread alternate name for the ice giant or gas giant class, and they are both two words. Jovian and Neptunian (derived terms, Jove being another name of mythological Jupiter) are adjectives and will not work. I think Jovia and Neptunia would be the best class names because they are both nouns and follow the -a pattern that most of the bulk classes have. They are also, as stated in the original post, the established exoplanet terms "Jupiters" and "Neptunes" (e.g. Hot Jupiters and Hot Neptunes) and will eliminate confusion about hot ice giants. Chthonia sounds good. Although chthonia is derived from Greek, it is already an established name of the hypothetical celestial object
. Thus, it should not be changed for simplicity's sake. Asteroid breaks the -a pattern, but because it is obviously an established name of a celestial object class, it should be a suitable name for the class in Space Engine.
Size - mega - super - (no prefix) - sub - mini - microThese prefixes have different orgins. However, some prefixes have already been adopted in class names of some celestial objects. For example, super- is a loanword from Latin and is used in "Super-Earth", but mini- is simply adopted by shortening the word miniature, which is from Italian miniatura, a type of small painting, and is used in "Mini-Neptune". Taking these
non uniformities into account, a ranking system based on what has already been somewhat established in astronomy would be better. I think mega-, super-, and sub- are suitable because they are already established in the giant "Mega-Earth
", Super-Earth class, and Sub-Earth class. Mini- is a interesting because a Mini-Neptune is still 10 M⊕
. It's suitable because it's been established as a class already. Micro- is also suitable because it is derived from Greek meaning small and is often used in cases where it means abnormally small (e.g. microcephaly).
Temperature - scorched/torrid - hot - warm - temperate - cool - cold - frozen/cryogenic/frigid
I think torrid and frigid are very good because they are opposite pairs. Warm is the opposite of cold. Hot is the opposite of cool. Torrid is the (near) opposite of frigid. They are also strong words that express their respective temperatures adequately. However, if, because of translation reasons, these words are undesirable, scorched and frozen certainly sound fine.
Atmospheric Pressure - airless - infrabaric - hypobaric - mesobaric - hyperbaric - ultrabaric
Airless is different from the -baric pattern, but I don't think there is any synonym of airless that is suitable for a celestial body devoid of an atmosphere. Meso- is fine as it means middle. I was thinking about normobaric, but I think that strictly applies to a pressure of 1 atm. Personally, I feel that ultrabaric should be suprabaric because supra- seems to be a better antonym of infra-. Don't get me wrong, ultra- is interchangeable, but infra- means "below", supra- means "above", and ultra- means "beyond". This is very pedantic but the opposite of below is above, not beyond. That's why I think suprabaric is a better is more suitable. Hypo- and hyper- are fine; they are exact opposites.
Atmosphere Breathability - toxic - unbreathable - breathable - bio-hazardous
I don't think there needs to be a hyphen between biohazardous. I'm not sure what the difference between toxic and biohazardous would be, but it sounds very difficult to measure (you would need to know the toxicity of every gas in the atmosphere. Perhaps an additional class called "training required" but that would be exceedingly difficult to categorize.
Additional Info - tidally-locked - volcanic - cryovolcanic - cometary - inhabited
Nothing wrong here! Sounds good. To solve the double tag problem, perhaps some tags could be a different color so that they stand out. The same could be done but with bolding or italicizing.
Volatiles Composition - pryo - thermo - (none) - hypo - cryo
I think thermo- and hypo- should be omitted because I can't think of a warm but not hot or cool but not cold volatile.
Volatiles Amount - desertic/arid - laky - marine - oceanic - superoceanic - glacial
As someone said earlier, xeric is the perfect word for desertic. (I learned a new word today!) Other than that, the other words seem to be fine.
Surface Class - metallic - rocky - carbid - icy - watery
I am not sure if carbid is a word, but I don't know any words that mean "made of carbon". Maybe someone could help me with that. Aqueous is a better word for watery in my opinion. Then again, you could consider any ocean of any liquid as aqueous whereas watery usually pertains to just water.