You keep assuming this world is a similar thing as the lights you observe above in the sky. No laws make this assumption fact, but granted it is required to stay in the heliocentric trap. Diameter is actually tiny - there's numerous observations across hundreds of miles, impossible with any reasonable curvature calculation, as required by the heliocentric model. One enthusiast (jtolan) calculated a radius in the millions after a long range observation from a plane with IR filter. Many a globe skeptics have been made by simply deciding to dig for definitive proof of a globe. There is none.