What you’ll learn4 learning objectivesChoose one objective for a focused lesson, or study the complete topic.6.1.1.1Earth rotates on its tilted axis once• Know the Earth rotates on its tilted axis once in about 24 hours; use this to explain the Sun’s apparent daily motion and the day/night cycleSyllabus objective6.1.1.2Earth orbits the Sun once in• Know: the Earth orbits the Sun once in approximately 365 days and use this to explain the periodic nature of the seasonsSyllabus objective6.1.1.3It takes approximately one month for• Know: it takes approximately one month for the Moon to orbit the Earth and use this to explain the periodic nature of the Moon’s cycle of phasesSyllabus objective6.1.1.4Average orbital speed• Define average orbital speed; recall/use: v = 2πr/T, where r is average orbital radius and T is orbital periodSyllabus objective