27. Rotates On An Axis
While the Earth rotates on a regular basis, this happens on an axis. This is obviously a good thing for a load of reasons. You want the planet to spin on an Axis to allow the planet to completely get needed heat from the sun.
If it just revolves around the sun, then one side of the Earth will be in total light and heat while the other is in total darkness and cold. This would cause several problems. An axis also helps the climate and weather of the planet. It even allows the Earth to go into seasons.