sentences: earth rotating on its tilted axis occurs once per day
docs: periodic_rotation is rotating. axial_rotation is rotation. earth_day is 24_hours_long. orbital_rotation is rotation. if wind occurs then turn occurs. every_fourth_year_earth's_year has 366_days earth's_year has 365_days ascension_day is day. rotation is motion. one_day_on_venus is 117_earth_days.