Question | Answer |
What are the two major ways the Earth moves through space? | Rotation and revolution |
Why does Earth have seasons? | Its axis is tilted as it revolves around the sun |
What two factors does the strength of the force of gravity between two objects depend on? | Masses of the objects and the distance between them |
What did Newton conclude about the two factors-inertia and gravity- combined do? | Keep Earth in orbit around the sun and the moon in orbit around Earth |
What does the changing relative positions of the moon, Earth, and sun cause? | The phases of the moon, eclipses, and tides |
What do the phases of the moon you see depend on? | How much of the sunlit side of the moon faces Earth |
When does an eclipse occur? | When the moon's shadow hits Earth or Earth's shadow hits the moon |
When does a solar eclipse occur? | When the moon passes directly between Earth and the sun, blocking sunlight from Earth |
What happens during a lunar eclipse? | Earth blocks sunlight from reaching the moon |
What causes tides? | Tides are caused mainly by differences in how much the moon's gravity pulls on different parts of Earth |
What are the features of the moon's surface? | Maria, Craters, and Highlands |
Compare the moon and the Earth with their sizes and surface gravity | Moon is dry and airless. Moon is 1/4 diameter of Earth and 1/80 of Earth's mass. Earth has a stronger gravitational pull because of the difference in mass (Earth=more mass) |
What do scientists theorize about how the moon formed? | A planet - sized object collided with Earth to form the moon. Then material from the object and Earth's outer layer was ejected into orbit around Earth, where it formed a ring. Gravity then caused the material to combine and form a moon |
What are solstices and equinoxes? How are they related to the seasons? | They are both changes in the seasons. They are related to the seasons because they mark the beginning of each season |
Suppose the moon were closer to Earth. How would the force of gravity between Earth and the moon be different? | The force of gravity would increase and be stronger. The tides would be larger too. |
How would Earth move if the sun (including gravity) suddenly disappeared? | Inertia would cause the Earth to travel in a straight line. |
How is a solar eclipse different from a lunar eclipse? | Solar: Occurs when the moon passes directly between the Earth and the sun, blocking sun from Earth
Lunar: Earth blocks sun from reaching the moon |
What causes the difference in tides? | Tides are mainly caused by differences in how much the moon's gravity pulls on different parts of Earth. |
Why is the moon's surface more heavily cratered than Earth's surface? | Earth's craters have worn away over time by water, wind, and other forces |
Why is it less likely to see a total solar eclipse than a total lunar eclipse? | The moon's umbra only covers a small area on Earth's surface |
What do scientists call the theory on how the moon was formed? | Collision - Ring Theory |
Lunar Eclipse | The blocking of sunlight to the moon that occurs when Earth is directly between the sun and moon |
Solar Eclipse | The blocking of sunlight to Earth that occurs when the moon is directly between the sun and Earth |
Spring Tide | The tide with the greatest difference between consecutive low and high tides |
Neap Tide | The tide with the least distance between consecutive low and high tides |
Weight | The force of gravity on an object |
Mass | The amount of matter in an object |
Law of Universal Gravitation | Newton's law that states that every object in the universe attracts every other object |
Tide | The periodic rise and fall of the level of water in the ocean |
Umbra | The very darkest part of the moon's shadow |
Astronomy | The study of the moon, stars, and other objects in space |
Equinox | The 2 days of the year on which neither hemisphere is tilted toward or away from the sun |
Penumbra | The part of a shadow surrounding the darkest part |
Eclipse | When an object in space comes between the sun and a third object, it casts a shadow on that object |
Gravity | A force that attracts all objects toward each other |
Phases | The different shapes of the moon you see from Earth |
Calendar | A system of organizing time that defines the beginning, length, and divisions of a year |
Force | A push or a pull |
Revolution | The movement of one object around another |
Newton's First Law of Motion | A scientific law that says that an object at rest will stay at rest and an object in motion will stay in motion with a constant speed and direction unless acted on by a force |
Rotation | The spinning of Earth on its axis |
Axis | The imaginary line that passes through Earth's center and the north and south poles |
Orbit | The path of an object as it revolves around another object in space |
Inertia | The tendency of an object to resist a change in motion |
Solstice | Each of these days when the sun is farthest north or south of the equator |