Chapter 1: Earth, Moon, and Sun
Section 1: Earth in Space
How does Earth move in Space?
Earth moves through space in two major ways; rotation and revolution.
What causes the cycle of seasons on Earth?
In addition to rotating on its axis, Earth travels around the sun. One complete orbit equals a year.
Section 2: Gravity and Motion
What determines the strength of the force of gravity between two objects?
It depends on the mass of the object and the distance between them.
What two factors combine to keep the moon and Earth in orbit?
Inertia and gravity keep the moon and Earth in orbit.
Section 3: Phases, Eclipses, and Tides
What causes the phases of the moon?
It depends on how much of the sunlit side of the moon faces Earth.
What are solar and lunar eclipses?
Solar eclipses occur when a new moon blocks your view of the sun. Lunar eclipses occur at a full moon when Earth is directly between the moon and the sun.
What causes the tides?
Tides are caused mainly by the differences in how much the moon's gravity pulls on different parts of Earth.
Section 4: Earth's Moon
What features are found on the moon's surface?
Features on the moon's surface include maria, craters, and highlands.
What are some characteristics of the moon?
The moon is dry and airless. Compared to Earth,the moon is small and has large variations in its surface temperature.
How did the moon form?
Scientists theorize that a planet-sized object collided with Earth to form the moon.