I think of it less of "is currently in orbit around a star" and more of "formed while orbiting a star"

For the record, Pluto's diameter is not what demoted it from planethood

Am... Am I a planet??

I love you

Pluto a planet?? My boy Neil de Grasee Tyson is gonna visit you realllll sooon.........

An option for the rock is that the majority of the forces keeping it together is gravity, as opposed to something like Van Der Waals forces like a one metre wide rock. And I know gravity is not literally a force.

As for maximum, I would make it so that being a sphereoid would be the threshold. They would become planets above it, although if they are in orbit principally around something that isn't a star or brown dwarf then they would be satellite planets, and if they can't clear their orbit and aren't satellite planets this would make them dwarf planets.

Also, I don't like using the word moon for these sorts of objects anyway, I would tend toward using satellites (or natural satellites). It gets confusing especially given that strictly speaking, the definitions I just gave would make the Moon not a lowercase moon.

I proposed on another thread (and note: with only a layperson's knowledge) that a "moon" should be a least 100 cu km to be considered as such; otherwise it'd just be considered a "natural satellite".

This isn't all that restrictive: Mars's famously small moon Deimos is still over ten times that volume, at 1033 cu km. A small hunk of rock just 6km (=3.75 miles) in diameter crosses the bar handily at 113 cu km. And Saturn would still have at least 42 (!) "real" moons of >=100km^3, which should be enough for any planet. Even the ones without any fancy-schmancy rings.

EDIT: Noting that most astronomers are going for size-based definitions for "moon", and ones much smaller than mine - like from 1000m (1km) all the way down to just 1m. (Really?) Also see my comment below re: why it's based on size, not mass.

The general definition of a moon is that it is orbiting a planet. So, what are we arguing about?! That a smaller object (like a caught asteroid) is not a moon although it is orbiting a planet?!

Source wikipedia https://en.wikipedia.org/wiki/Natural_satellite :

There is no established lower limit on what is considered a "moon". Every natural celestial body with an identified orbit around a planet of the Solar System, some as small as a kilometer across, has been considered a moon, though objects a tenth that size within Saturn's rings, which have not been directly observed, have been called moonlets. Small asteroid moons (natural satellites of asteroids), such as Dactyl, have also been called moonlets.^([12])

The upper limit is also vague. Two orbiting bodies are sometimes described as a double planet rather than a primary and satellite. Asteroids such as 90 Antiope are considered double asteroids, but they have not forced a clear definition of what constitutes a moon. Some authors consider the Pluto–Charon system to be a double (dwarf) planet. The most common^([)^(citation needed)^(]) dividing line on what is considered a moon rests upon whether the barycentre is below the surface of the larger body, though this is somewhat arbitrary because it depends on distance as well as relative mass.

If a red bicycle is a bicycle, then a dwarf planet is a planet.

If Pluto qualifies as a planet then there are quite a few other objects that also qualify, and we’d have maybe 50 planets not 9.

I refuse to stop calling Pluto a planet, and I %100 support rereclassifying it as such. It's okay if the definition of a word is more about vibes that objectively observable traits.

Also the little rhyme goes my very excellent mother just served us nine pizzas

Come on it's a planet and so what if recognition of that would prompt the relabeling of other celestial bodies or the creation of new categories such as "classical planets" or whatever.

Nevertheless we don't need their approval to respect Pluto's planethood, I refer to it as the planet it is as do many others and it's catching on, probably because it's a planet.

No one ever called the United States a planet.

Texas is bigger than France. So what?

No, other planets have moons. Our moon is just called "the Moon"

I used to think that, but people call the satellites of Mars "the moons of Mars."

Just like we call the satellites of sun "the planets and Pluto". 

The name of the moon is "Moon". Same for the sun, it's name is "Sun". 

Until very recently there was only one moon known to humans. So they looked up and called it "Moon". Same for the sun. And then we found out there were other things like our moon, but we only had the name moon so we called all the other things like moon "Moons"..And then we realised all the stars were actually things exactly like sun. So we called them all suns.

Sol is the name of the star, which performs the role of our sun because we revolve around it.

Luna is the name of our moon, which would be a planetoid if it weren't revolving around us.

No, the formal names for the Earth, the Moon and the Sun are the Earth, the Moon and the Sun. This is reality, not Warhammer.

Star means those pinpricks of light peaking through the sky dome. The ones we eventually figured out were like Sol but vastly further away. "Planet" means "wanderer" because unlike the other pinpricks then move.

Also, the reason nobody calls the sun "the star" is probably because we can see tons of other stars. "The moon" is really the only moon that's relevant to our lives in any way unless we're specifically talking about space stuff.

That does nothing for all the Romance languages that already call the moon Luna or Lune and also use the same word to describe moons around other bodies. Not everyone speaks English.

You may want to look into etymology of these words because that may give you the explanation you are really looking for regarding what "star" means / its name's origin. Google "Etymology of the word star"

The Moon's name is Luna, but is a natural satellite of Earth. Moon = Luna = Satellite

The Sun's name is Sol, but it is the star Earth orbits. Sun = Sol = Star

The Earth's name is Terra, but it is the planet we live on. Earth = Terra = Planet

Different languages will call these same celestial bodies different names, and science has terms that define similar celestial bodies in a general way. Most of the Solar System's "Heavenly Bodies" are named for Roman Gods, but have generic terms. Star Bucks (specific brand) is a coffee shop (general term).

Labelling rows top left to bottom right:

1 - Ceres is a planet

2 - The Solar System has a big planet belt outside Neptune, and at least three planets between Mars and Jupiter

3 - The Parker Solar Probe is a planet

4 - Cygnus X-1 and Sirius B are planets

5 - I like this one as it is

6 - There's a reservoir of millions of planets between Mars and Jupiter and a belt of artificial, but real, planets around Earth

7 - Eta Carinae and Betelgeuse are planets

8 - This one is good too

9 - Your phone and an Airbus A380-800 are both planets

The Pluto earth distinction for dwarf planets isn’t a diameter threshold, it is if it is significantly larger than anything else in its orbit. This table still works if the rows for above a certain diameter and any diameter are changed to has cleared its orbit and hasn’t cleared its orbit.

Check the discovery tab, it'll show which planet the moon is orbiting

Maybe the moon is actually the planet and the "planets" are actually the moons???

Joint custody

They have joint custody and rotate on weekends

Yes

Now, if it was titled "You won't BELIEVE what SCIENTISTS have discovered about the MOON (NOT CLICKBAIT) (REAL)," now that'd be a good title.

My 3 year old told me 2 days ago his dream was to dig up dino bones on the moon. I feel he might have inside knowledge.

Definitely, the headline wording is a little annoying to me. They clear it up at the top of the article but the idea that the moon came from a collision with the earth is pretty old.

Alternative wording: “New evidence supports theory that the Moon was Once Part of Earth”

Don't think of it as "breaks off". It's more like the Earth got liquefied and a blob of magma spun off into space. Bloop. And then both blobs re-hardened.

Yeah, that's why the title says "new evidence points to" and not "evidence points to new theory". Pretty simple concept. New evidence can add support to the leading theory, crazy.

It basically erased the surface rocks and flung them into space. Computer models that take into account the differing composition of Earth and Moon show Theia striking proto-Earth at a low angle, with the surfaces of both planets mostly jettisoned into space, with most of Theia's heavier interior, including metals, sinking towards Earth's core.

The result was not comparable to any asteroid strike. Earth was basically destroyed and remade; most of the (lighter) material that escaped the collision became the Moon.

I feel like a lot of people didn't read the article or at least understand it. They aren't saying this is a new theory. They even list reasons why this was already an existing theory.

This article highlights new evidence that further supports this theory.

It’s already broadly accepted as the most likely theory with the evidence we have and is the main theory taught in earth history classes. There is a plethora of reasoning based on the geology of the moon and its size and shape that support the theory.

Edit: because it’s confusing a lot of people, here is a comment where I link to “Earth History” classes taught at colleges. It is not a branch of human history but is instead classified under geology.

Pretty sure the planet we see in the sky from Kenshi is actually a gas giant. I feel like the first empire was a. Spacefaring civilization that colonized Kenshi but it's not actually confirmed. It's possible this is an alternate universe and Kenshi was the original celestial body that human life originated from. In any case, the first empire definitely at least had satellites

I thought it was a gas giant or carbon planet. Something big enough that the moon can have an Earth-like gravity and atmosphere.

The moon itself has those huge patches of hydrocarbons in the tar sands concentrated around BDC, kind of like Titan.

Kenshi 2: this is where we should have landed

I would be interested in additional content that could transport us to the planet... maybe if there is a Kenshi 3 during the First Empire. But that'll be in like 20 years if at all. :)

Why does this comment section give me borderlands vibes.

Just like the "face on Mars", it's just another rock.

I am an early career planetary scientist who has been following the progress of rovers for 10 years & scientifically studied rocks in their images before. It is a boulder. I can guarantee it.

In fact, I bet it isn't even cube shaped. The photo that went viral is like 8x8 pixels across, with a smoothing filter applied. That is why it looked cubic/artificial. When we get closer it'll just be another rock. But that's fine!

edit: It is even lower resolution than I thought.

I have been surprised how much this comes up. We only saw a very low resolution picture, and only from one side, and only in one direction of sunlight, and yet everyone started calling it a cube.

Shadows and camera resolution issues are tricking human optical system into thinking there is something regularly-shaped when it will turn out to be just a rock no different from any other large ejecta on the lunar surface.

Just a rock. Some time ago I was looking at the images from the area and there is a crater nearby that looks like the source of many rocks this size and shape. Possibly something like a columnar basalt formation got impacted by an asteroid and spewed some of these rocks over a large area.

Human brains like patterns. Realistically speaking, there’s nothing particularly strange or rare about cubes forming in nature. Look at salt crystals or Pyrite. The moon has experienced many collisions over its life and it’s more than likely one just happened to make a square rock. It’s interesting to be sure, but I doubt it’s special in any way.