Neptune does not clear Pluto's orbit.

[RedDevil]

Nibiru is fringe science at best.

The word Nibiru comes from the writings of the Azerbaijani American author and ancient astronaut theorist Zecharia Sitchin.[19]

I have it on good authority that 'Ni biru' means 'Two beer' in Japanese, which may as well give a clue to the source.

Which reminds me of...

https://www.youtube.com/watch?v=neoUi4poCXI

[Natalya]

二ビール
Ni Biiru
Hahahaha!!

Sadly this doesn't actually work in Japanese. They stick "counter words" in everything where you're naming a number of an object. Different types of objects get different counter words. The counter for glasses of a drink is "hai" so you'd have to say ni-hai biiru.

二杯ビール
Also written as:
にはいビール

Also whoever wrote that thing about Nibiru with that terrible diagram is out of their mind.

[freebeard]

Thank goodness you didn't say "whoever posted it".

Duck Duck Go picked it out.

[jamesqf]

Originally Posted by Xist

These are celestial bodies. Is Sol the same class as the rest? No. Is Luna? No. Also, does anyone argue that a moon is a planet?

Why should the moon not be considered to be the same as a planet in most practical ways? It's big enough to be round, is internally differentiated, has a bit of geology going on...

If not Luna, how about Titan? It's got an atmosphere, with oceans (or at least big lakes) & rivers, which is more than Mercury & Mars have.

[redpoint5]

It all seems more arbitrary than many other systems of differentiation. Perhaps we should classify things in terms of what they are a "moon" of, meaning what they orbit. The Earth is a moon of the Sun, and the Sun is a moon of the galaxy, and the galaxy is a moon of the universe.

The most widely held theory is that the moon is comprised of partly some object colliding with earth, and taking a chunk of it away. Maybe we should call it earth theif?

Anyhow, what I don't get is if the moon is partly composed of earth, then why aren't the same diversity of elements and compounds found there?

[freebeard]

The most widely held theory is that the moon is comprised of partly some object colliding with earth, and taking a chunk of it away. Maybe we should call it earth theif?
Anyhow, what I don't get is if the moon is partly composed of earth, then why aren't the same diversity of elements and compounds found there?

Which theory fails to account for the exact size and distance compared to the Sun.

Originally Posted by DuckDuckGo

But then why is there such a big difference between the specific gravity of the Moon (3.33 grams per cubic centimeter) and that of the Earth (5.5 gr.)? Furthermore ...

Also it rings like a bell.

[Vman455]

Originally Posted by redpoint5

Anyhow, what I don't get is if the moon is partly composed of earth, then why aren't the same diversity of elements and compounds found there?

They are similar; the two most abundant elements in the earth's crust are oxygen and silicon, which together make up more than 75% of the crust by mass. The moon's surface has a similar chemical composition, more than 60% oxygen and silicon.



By "same diversity of elements and compounds," I assume you mean things like organic molecules. Having an atmosphere really helps with that--which was instrumental to the development of organic molecules here on Earth.

[Vman455]

Originally Posted by freebeard

Which theory fails to account for the exact size and distance compared to the Sun.

Also it rings like a bell.

While the average density (g/mL is a calculation of density, not specific gravity. Mass is a property that exists independent of gravity, and mass per volume is a derived unit) of Earth is 5.5 g/mL, and the average density of the moon is 3.3 g/mL, these numbers include the molten cores and mantles of both bodies, which is relatively much larger for Earth and skews its overall average density higher. The average density of Earth's continental crusts, which are slightly less dense than oceanic crust, is 2.67 g/mL, while the average density of the Moon's crust is 2.55 g/mL.

[freebeard]

??? You cut out the part where I was quoting someone else? (DDG since I didn't evaluate their link)

I agree that it's more likely the old Pacific not-ocean flung into space. I thought it was doubtful anything could penetrate to the core. The impact that led to the Snake River basin and Yellowstone apparently only penetrated 40-50 miles into the Earth's mantle.

Now I have to go look whether the Moon even has a core. ... Yup.


https://en.wikipedia.org/wiki/Intern..._the_Moon#Core

Several lines of evidence imply that the lunar core is small, with a radius of about 350 km or less.[3] The size of the lunar core is only about 20% the size of the Moon itself, in contrast to about 50% as is the case for most other terrestrial bodies. The composition of the lunar core is not well constrained, but most believe that it is composed of metallic iron alloyed with a small amount of sulfur and nickel. Analyses of the Moon's time-variable rotations [!] indicate that the core is at least partly molten.[4]

Does it stutter?

[niky]

Originally Posted by jamesqf

Why should the moon not be considered to be the same as a planet in most practical ways? It's big enough to be round, is internally differentiated, has a bit of geology going on...

Many have pointed out in the past (and present, I guess) that you could call the Earth-Luna system a binary planet, given the size of the moon in relation to its primary.

Well, not quite a binary system, as the center of the orbital system lies somewhere in the Earth's mantle. Give the moon a few million (a few ten million? hundred million? a billion?) years to wander further away and the center will be outside of Earth... at which point you will now have two planets (or one planet and one dwarf) orbiting a common point that is orbiting around the sun.