Earth has many admirers, but, the two most persistent are the two brothers named Sun and Moon. Nothing can stop their rivalry for Earth's affections, not even their brotherhood.
The brothers know something that the other admirers don't. Earth has inhabitants and she calls them people. Earth loves them so much and she would do her best to keep them satisfied. Knowing this, Sun and Moon tries to outdo each other.
Sun keeps telling Earth that he'll keep them warm and safe. Moon on the other hand tells Earth that he'll keep them cool and away from Sun's heat. Earth can only smile, for she knows that they need both Sun and Moon.
Up to this point, Sun and Moon are doing their best to win Earth's love. Sun and Moon had an agreement, Sun will have the day while Moon will have the night.