@Jim Prower  
Unfortunately, there are a number of problems with this. For example, seasonal change is somehow a local event, not one dictated by hemispheres like ours are.

I somewhat like the idea that (If Equestria is indeed on a planet and in a universe like the one we know - which, it may entirely not be and thus this is entirely null,) that at some point it and its two moons were flung out of orbit of it’s original star by a large gravitational body passing nearby. Thus, to support it, Celestia and Luna must each control one of the two moons - the “Sun” is actually a “Burning Moon,” heated up anew every morning by the use of a…well…positively massive fire spell. Season changes might be caused by changing the orbits of the satellites, both of which would have to be changed to keep things stable. It’s likely Luna would have to light up the moon herself, for if the Sun and Moon were opposed from one another, it’d impossible for sunlight to reach it through the…earth? I can’t rightfully think of a way to make the system stable without the Earth being between the Sun and Moon.
 
Granted, this doesn’t account for the stars, unless somehow or for some reason they’re a ‘blanket’ to cover for the fact that the planet’s zooming through space over time…But, like people say, it’s a cartoon…the point of things like this isn’t if it’s true, but plausible. There’s simply too many variables in a cartoon, particularly one not particularly concerned with the physics of its universe. X3
 
I do agree that their Sun and Moon would likely be much smaller masses than Our Moon, and are probably closer - it would account for a day/night orbital period similar to ours.

@Background Pony Number 17  
Counterpoint: the book about comets in Owl’s Well That Ends Well. (No idea how the Fourteenth Moon from It’s About Time fits in.)

@Background Pony #56A3  
In the comics (not sure how canon that is), when they have to go to the Moon to fight/save Rarity, Luna (with help) first pulls it towards the Earth so it is hardly any distance at all from the ground. The comic shows how big it is, and whilst it is still a very big object by everyday standards, it is nowhere near the size of the real life Moon.

Oh god. [dies laughing] This is hilarious.

@Background Pony #6508  
That…actually makes all kinds of sense.

I’ve seen the theory that Equestria doesn’t have a proper sun, it’s a magical construct. The universe that Equestia inhabits is nearly dead and magic is the only thing keeping it working properly, that’s why pegasi have to control the weather and such.

This is conjecture based on fanon? Some people really have too much time on their hands.

Of all the images on this site…
 
this is one of them.
 

 

 
 
I don’t like this.

@Background Pony Number 17  
I was just going to say something about that. People tend to automatically think of the Equestrian universe as being cosmologically identical to our own, when that obviously cannot possibly be the case.

ITT no one can into Ptolemy.
 
Equestria is contained in a geocentric Universe. The Sun, Moon and stars are held in invisible crystal spheres that are turned by Unicorn magic, moving the heavenly bodies across the sky. Since all of the stars are fixed in single crystal sphere, moving them is no more difficult than moving the spheres that hold the Sun or Moon–easier, in fact, considering how small the stars are.

Really, where did people get the idea that Luna controls the stars as well? All we know is that she guards he night and raises the moon, nothing was ever mentioned about the stars.

XDDDDDDDDDDDDDDDDDDDDDDDDD….so that’s why!

it’s quite amazing how many people take this seriously..
 
either way, I’m not a fan of this,, but this was well done and I actually laughed a little at Celestia’s expression. It was simply priceless. :p

I’m pretty sure that Celestia did both her and Luna’s job during the thousand years that the latter was banished. So, it seems that they both can do each other’s job but have a deeper connection to their respective celestial bodies due to their cutie marks.

When does it ever say Luna controls the stars? I thought that was a fanon thing?

There is a reason why you don’t add realism in a cartoon. Things just fall apart when you add logic to it.

Brilliant, sir! Absolutely brilliant!

Okay that’s it, I am going to set off on a quest to find the means to defeat the evil sunbutt.  
Now where should I start?  
 
Oh thanks Buddha.

The sun requires a bit more than raw power. It needs that power to be handled with surgical precision. If Rigel or Betelgeuse are nudged one or two parsecs out of place, nopony cares except a few bitchy astronomers. If the sun is misaligned by even a fraction of a parsec, everypony dies.

Hahahahah! Oh, that’s great.

Incoming headcanon:
 
The inverse-square law applies. The stars are much further away, and thus give much less power. Collectively, combined with the moon, they put Luna roughly on par with Celestia.

 

New headcanon accepted.