Mass illusion spell would be my guess. Maybe some Alteration in there too.

I just don't see how the Thalmor would be able to create any spell powerful enough to do something like this. To hide two moons from all in, at least, Tamriel would require more magic at play then I have ever seen before. Also if the moons were to dissapear and the Khajiit would still be born in their regular cycles, don't you think they would start to wonder if a. the moons are really gone? or b. if the moons are trully as important as they previously believed?

You can see the new moon. Unless the moons started a geosynch orbit over Akavir (perhaps to battle the Ka'Po'Tun?) they'd be visible to anyone who is sharp-eyed.

By being powerful enough to cast such a spell?

The whole obsession with completely denying this event seems nonsensical to me. We don't deny that Zurin's soul was powerful enough to serve as a surrogate heart of Lorkhan. We don't deny that the mirror-mages and the Brass-Walk are powerful enough that when they clashed, the battle lasted for thousands and one year at once. We don't deny that arteum travels around. Why deny that the moon disappeared?

Now, for sure, we should place some limitations on Thalmor magical power. Clearly, for example, they're incapable of waging a successful direct battle with the Psijiics. Clearly, their grasp on destructive magic isn't such that they can just nuke Cyrodiil. But what reason do you all have for denying that either the moons disappeared, or that the Thalmor are capable of casting a giant illusion spell to make them invisible?

Now, doubting that the moons genuinely disappeared, and then the Thalmor returned them to the sky, because it doesn't fit with their motives, makes perfect sense. A lot of other criticisms make perfect sense to me. But I haven't yet seen a good answer as to why the moons couldn't have really disappeared, or why the Thalmor couldn't have really tricked the Khajiit using illusion magic.

I'm not denying the moons dissapeared, I honestly believe they did. This event is not something that was just made up, I just don't see how the Thalmor could do it. But the points you made, do make sense. It could be possible for them to do something like that. Then it could also have been Divayth Fyr who learned of a possible Khajiit invasion into Morrowind and decided to give them other priorities, that's my point it's entirely speculative.

Besides the Thalmor taking credit for their return we have nothing linking the Thalmor to this, and we know the Thalmor are quite capable of taking credit for things they didn't do... But again, I guess that my thinking they aren't powerful enough doesn't make that much sense looking at other things other mages have done in the past.

Again, it really is more a question of motive than ability.

That makes perfect sense. Thanks!

I think the "Mane" might actually be the Khajiit "tower." When the moon's disappeared, the Thalmor were probably like "[censored], that means we can get rid of the tower," because of a new Mane being born under three moons. But when they found that they were coming back, they decided to exploit it politically so they would at least be able to control the Khajiit.

I am probably talking rubbish, but bear with me. Just some ideas, 'cause I hate the illusion spell idea. Anything is better.

Lorkhan is an infinite plane. A dead one, but the moons are just the physical reality that the inhabitants of Nirn can comprehend and cope with. What if the stuff about the dawn era actually being the end of the last world is right? Shor is back, ready to start the new Kalpa, same as the old one, with man there throwing the spanner in the old 'escape creation and unwind the coils' plan. IIIIIIII to 0000000I, do not pass 00000000, do not escape linear time. [Lose the arrogance, learn some loving, only way to transcend.]

The greybeards are unfussed about Alduin destroying the world. The Psiijics don't seem to care, tracking a big blue ball being much higher on their list of priorities. What do they know that everyone else doesn't? The world doesn't really end, maybe? Just starts anew with a big chunk of business as usual. Is that the trap? The moons disappeared because the plane was undergoing birthing pains or parthenogenesis. [Lorkhaj born in the great darkness.]
Shor son of Shor is in the sky (those moons look a lot bigger now, it has to be said), not broken in two due to being killed, but in two waiting to fully form. [Why not one again? Tricksy. Why afoot later as the last Dragonborn, the last Shezzarine, who isn't even necessarily human? Even tricksier.]
Quite apart from using the opportunity to hoodwink the Khajiit, wouldn't that be just the signal to set the Thalmor off desperately planning wars, eradicating man, and trying to erase Talos and all he represents, Lorkhan-wise? Before it's too late, and the same old show must go on.

Shor the dead remnant is gone, Shor the Embryo?/Egg?/Protoform? is here, now featuring in an aurora near you. Bring on the dawn age weirdness.

But I thought the moons' phases were due to their rotation displaying the transparant/rotted-away areas to Nirn. Surely a properly renewed Shor wouldn't still be full of holes?

Khajiit are the Tower, the Mane is the Stone.

It could have been some Akviri thing. Maybe the moon were constantly floating over Akavir for 2 years, abandoning their orbit. We don't know what goes on over there.

Nor should we care what's going on in Akavir, as there is almost nothing on Akavir, save for highly outdated books.

My point being, they might later explain this epic stuff using Akavir. Besides, Akavir is, as far as we know, a land of constant war. Tamriel can't have all the epic stuff.

So is Tamriel. Or it was, until Talos created the Septim Empire.

Tamriel also doesn't have Kamal.

Ghraal.

Kamal means snow hell. Not Ghraal.

The moment the game features a location in game; all the epic goes away.
so far.

Sadly true. The hardware and software is getting better though. Next game will be next gen.

I meant as in "you wanted snow demons, we have Ghraals. Close enough in my book, and those [censored]ers do look cool.

I've suspected it would be an Oblivion-esque event; some unknown prisoner and champion enters Elsweyr as the moons disappear. He/she investigates, uncovers a much bigger mystery/quest and embarks on an epic journey that sees the moons return, but the Thalmor take credit like they did for the Oblivion Crisis in Summerset Isle.

Udyrfryktes looked pretty cool, too. :'(

Would the assassination of the Mane and the disfunction of the tower afterwards, i.e. a split between Pellentine and Anequina, be a cause for Jode and Jone's disappearance?

They weren't unified until 2E 309. Why would the split affect the moons now, but not affect them when the land was divided in the past?

They split again in the 4E 115. The moons disapeared in 4E 98, the Mane was assassinated before then in the first year of the fourth era. Perhaps the effect of the cause relating to the assassination wasn't finalized until later? I'm just hazarding a guess.