I should probably say first off that if you're someone who doesn't like attempts at scientific explanations of events in Star Wars, you probably won't like this blog

Something's been nagging at me lately about the Death Star, and it was actually brought on by a series of blogs by jedilaura28, in regards to orbits and gravity in the battle above Corsucant in Episode III.

The Death Star. A small moon-sized space station. The first one, according to the database on starwars.com, was 120 kilometers in diameter, the second one was 160 kilometers in diameter. Now granted, compared even to our own moon which is 3476 kilometers in diameter, this is very small. Yet it still dwarfs even the largest starship known to have been built in the Wars universe, the Executor, which is some 19 kilometers in length.

Furthermore, let's look at the composition of these Death Stars. Now obviously I don't know all of the different alloys that have been invented in the Wars universe. We can assume all windows are transparisteel, which to my knowledge is essentially transparent steel. And we can assume that the hull is made up of a very thick layer of alloys that likewise cover Star Destroyers and the like. We can also assume that the majority of the interior of the Death Stars are heavy alloys, mostly metal composites and the like. IE: everything that makes up the Death Star is heavy. Now granted because of corridors, garbage facilities, and a wide open space inside of the core, it's not super dense or super massive.

However, the fact remains that without a structural integrity field, gravity dampers of some sort, and of course artificial gravity, this 'small moon' probably would have crushed itself or torn itself apart. They probably had the same amount of mass as a medium moon, possibly a large one.

Now recall physics. Bodies of mass effect one another through gravity. To better explain this, I'd like to quote Jedi Laura from one of her blogs, since she quoted Newton and I honestly couldn't remember the words Newton used exactly

"According to Newton's "law of universal gravitation" the force of attraction between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between them."

So in other words, a basic tenant of these laws is that mass determines gravity, not size. That said, this 'small moon' should greatly effect worlds it approaches through tidal forces (IE: depending on how close it approached, Alderaan probably experienced an unusually high tide on half of it's surface, while the other half experienced an unsually low tide.)

So the question is: what happened when the Death Stars blew up? Now obviously they weren't massive enough to create an effect anywhere close to similar to a star supernova, that's obvious. Were they massive enough to leave behind a...well what would you call it, a small gravity shadow? I don't know how to explain it. I don't know if it's possible either, probably not.

However, there is an interesting theory about how certain planetary rings have formed around some planets. A moon's orbit grows far too close to its mother planet, or a rogue planet/comet/asteroid comes too close to a planet, and through the tidal forces the larger planet exerts, these moons, etc are torn apart and, over the course of thousands of years, spread across to become the rings of a planet.

So, unless recovery teams eventually come to claim all of the metals, etc left behind, it's entirely possible that in several hundred, or thousands of years from the battles of Endor and Yavin, they'll have brand new planetary rings made up of mostly heavy metals.

But I digress. The problem is tidal forces. As I mentioned above, depending on how close the Death Star approached Alderaan, or the fact that the Death Star II was so close to Endor, these planets likely experienced unusual oceanic tides. However, please note once again that the Death Stars should be fairly massive structures, and in particular, the Death Star II was obviously very close to Endor. Thanks to their structural integrity fields, they could approach planets and not have to worry about tidal forces tearing them apart (otherwise the first death star wouldn't have made it halfway around the gas giant...) Were they close enough to cause unsual tectonic activity in these worlds? I wonder, as the second Death Star gained mass, did Endor begin to experience an unusual amount of earth quakes (ok, so really it'd be called Endor quakes) It would have been interesting to see in RotJ a line from Threepio, translating for the Ewoks, about the appearance of the mystical orb and the accompanying ground shakes and water rising to new levels and the like.

Anywho, not trying to make any point in reality, just pointing out some interesting scientific facts about the Death Stars. If there's anyone who's better versed with physics, I beg you please point out any errors I've made and suggest corrections. I'm no expert, I just know what I know from basic Physics and Astronomy.