It acts like it's hollow and "rings" when struck. It's at a spoopy distance to perfectly allow eclipses. It's also in a perfect geo synchronous orbit so we can only ever see one side. If it wasn't there to stir the oceans, life may not exist as it does.
It's not a Death Star though. I think it may be more accurate to call it a Lifestar. It seems like it was put there.