Earth, Moon, and Sun
By: Keirstan Mesnick
Section 1~ Earth in Space
~ How does Earth move in space? * Earth moves through space in two major ways: rotation and revolution. -revolution= The movement of one object around another.one complete revolution of Earth around the sin is called a year. -rotation= Earth's rotation causes day and night. as Earth rotates eastward, the sun appears to move westward through the sky.
~ What causes the cycles of seasons on Earth? * Earth has seasons because its axis is tilted as it revolves around the sun. If Earth's axis were straight up and down relative to its orbit, temperatures would remain fairly constant all year round.
Section 2 ~ Gravity and Motion
~ What determines the strength of the force of gravity between two objects? * The masses of the objects and the distance between them determines the strength of the force of gravity between two objects.
~ What two factors combine to keep the moon and earth in orbit? * The two factors that combine to keep the moon and earth in orbit are inertia and gravity. Earth's gravity keeps pulling the moon toward it, preventing the moon from moving in a straight line. The moon keeps moving ahead because of inertia. If not for Earth's gravity, inertia would cause the moon to move off through space in a straight line.
Section 3~ Phases, Eclipses, and Tides
~ What causes the phases of the moon? * The changing relative positions of the moon, Earth, and sun cause the phases of the moon,eclipses,ans tides.
~ What are solar and lunar eclipses? * When the moon's shadow hits Earth or Earth's shadow hits the moon, an eclipse occurs. When an object in space comes between the sun and a third ob * A solar eclipse occurs when the moon passes directly between Earth and the sun, blocking sunlight from Earth. The moon's shadow then hits Earth, so a solar eclipse occurs when a new moon blocks your view of the sun. * During a lunar eclipse, Earth blocks sunlight from reaching the moon. The moon is then in Earth's shadow and looks dim from Earth.
~ What causes the tides? * Tides are caused mainly by differences in how much the moon's gravity pulls on different parts of Earth. The force of gravity pulls the moon and the Earth (including the water on Earth's surface) toward each other.
Section 4 ~ Earth's Moon
~ What features are found on the Earth's surface? * Features on the moon's surface include maria, craters, and highlands. -maria= The moon has dark, flat areas, which Galileo called maria, the Latin word for seas. -craters= Galileo saw that the moon's surface is marked by large round pits called craters. Craters are caused by the impacts of meteoroids (chunks of rock or dust from space). -highlands= Galileo correctly inferred that some of the light-colored features he saw on the moon's surface were highlands, or mountains. The peaks of the lunar highlands and the rims of the crates cast dark shadows.
~ What are the 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. If you were to visit the moon, you would need to wear a bulky space suit to provide air to breathe, protect against sunburn, and to keep you at a comfortable temperature.
~ How did the moon form? * Scientists theorize that a planet-sized object collided with Earth to form the moon. Material from the object and Earth's outer layers was ejected into orbit around Earth, where it formed a ring. Gravity caused this material to combine to forn the moon.