a dysan sphere is a thoerie, make a giant structure that engulfs an entire star system and its planets and it basicly means you can retain all the engerey in the system , they are huge, our one would have all 10 planets there moons in and the sun and comets etc
DON'T ANYONE CORRECT ME ON THERE BEING NINE PLANETS LOOK UP SEDNA BEFOR YOU START I SPENT NEARLY A WHOLE DAY LEARNING ABOUT THAT GOD DAM PLANET!
Actually that is somewhat incorrect. A Dyson's Sphere is used to enclosed a star and only one or 2 planets. The other planets in the system are broken down and processed for raw materials in order to build the sphere itself. Most Sphere's don't even encompass a planet, just the star, for the obvious reason that once built, the total surface area to live on will be...inestimable. Significantly larger than if you could live on the surface of every single one of the original planets in the system.
As for who actually built the Enterprise Sphere....who knows. The Iconians are a good guess, but it kinda seems uncharacteristic of them to me. I would hypothisize it was some heretofor unknown and now extinct race. Though what could cause a race capable of constructing a Dyson Sphere to go extinct I have no idea. More probably the evolved to a higher plane of existence or simply left the Galaxy in search of something better.