Find out why our planet spends half its time in darkness and the other half in sunlight. Physical processes -The Earth and beyond - Sun, Earth and Moon Learning Points The spin of the Earth causes day and night. The Earth orbits around the Sun. The Earth spins anticlockwise on its axis once every 24 hours. At any time half of the Earth is facing away from the Sun. A Twig Curriculum Film. Delivering key learning points. Get straight to the facts in just three minutes – directly linked to core learning, Twig's curriculum films will fit neatly into your lesson plans.