The sun, moon, stars, clouds, birds, and airplanes all have properties, locations, and movements that can be observed and described.
Changes in the Earth and Sky
Objects in the sky have patterns of movement. The sun, for example, appears to move across the sky in the same way every day, but its path changes slowly over the seasons. The moon moves across the sky on a daily basis much like the sun. The observable shape of the moon changes from day to day in a cycle that lasts about a month.
For Grades: 5-8
Earth in the Solar System
Most objects in the solar system are in regular and predictable motion. Those motions explain such phenomena as the day, the year, phases of the moon, and eclipses.