I thought of this when I read something someone wrote about Summer Star being on a cloud. And want to explain how they can get up on the clouds. For ponies are asking questions.
Their parents are celestial ponies. Ponies that Create and Control the Stars and the Movement of the stars in their world. Cosmos Creates the Stars and Galaxies and Dark Nebula Controls their movement and light energy.
Being this they must live in the stars. Because of their unique abilities and characteristics they have the ability to call the light of the stars to their hooves as they walk (it is a natural ability to them they don’t have to think about much like our breathing or blinking). The light fades after they step off of it. This light acts as a step holding their weight with ease (I know its ilogical and impossible for some to believe but as my friend says “Its a Shut up it’s magic thing” :dummy: . If they try they can also call upon this power and use it to help other unicorns or earth ponies to walk on air (so to speak). But they must concentrate for this to happen. If they use this power on others they will also be able to stand on clouds like the Star Sisters for a twenty four hour period without falling through.
Being the daughters of such parents they inherited this ability. Summer Star chose to come to Equestria because she wished to follow her own path. Winter Moon being as close as she is with her sister, though she had just come into her healing powers, chose to follow her (with her parent’s blessing of course).
They have been lighting the night ever since for ponies everywhere. Making Equestria their home.