Introduction

= = = = = = =// Introduction- //= =‍**Introduction**= This lesson addresses the comparison of the physical features of the Sun, Earth, and Moon and the pattern of day and night. According to the American Association for the Advancement of Science (AAAS), in the Benchmarks for Science Literacy (Project 2061) [on-line version],  by the end of 5 th grade, students should know several concepts: Earth is one of several planets that orbit the sun, and the moon orbits around the earth; The rotation of the earth on its axis every 24 hours produces the night-and-day cycle. To people on earth, this turning of the planet makes it seem as though the sun, moon, planets, and stars are orbiting the earth once a day; and the earth is approximately spherical in shape. Like the earth, the sun and planets are spheres . ||
 * Sun, Earth, and Moon Systems[[image:multi-media2011/5386057.jpg width="546" height="306" caption="5386057.jpg"]] **

American Association for the Advancement of Science. (2009). //Benchmarks on-line//. Retrieved December13, 2011, from [] .