Earth, Moon, and Sun!
by Bella Benz
Section 1: Earth in Space
How does Earth move in space?
Earth moves in space in two different was: rotation and revolution.
The spinning of Earth on its axis is called rotation. Earth's rotation causes day and night. It takes Earth about 24 hours to complete one rotation.
Earth also travels around the sun. The movement of one object around another is a revolution. A year is one full revolution around the sun. Earth has an orbit that it follows as it travels around the sun.
What causes the cycle of seasons on Earth?
Earth has seasons because it has a tilted axis as it revolves around the sun.
Summer is caused by Earth's axis tilting towards the sun. When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere.
Winter is caused by Earth's axis tilting away from the sun. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere.
When it is fall in the Northern Hemisphere, it is spring time in the Southern Hemisphere.
When the sun reaches the greatest distance north or south of the equator it is called a solstice. There are two solstices that occur on June 21 and December 21.
When neither hemisphere is tilted away from or towards the sun it is called an equinox. There are two equinoxes that occur on March 21 and September 22. These dates mark the beginning of spring and fall in the Northern Hemisphere.
Section 2: Gravity and Motion
What determines the strength of the force of gravity between two objects?
The strength of the force of gravity between two objects depends on two factors. Those factors are the masses of the objects and the distance between the two.
If the mass of the object increases, then the force of gravity will also increase.
If the distance increases, the force of gravity will decrease.
What two factors combine to keep the moon and Earth in orbit?
The two factors that combine to keep the moon and the Earth in orbit are inertia and gravity.
Inertia is the tendency of an object to resist a change in motion and gravity is the force that attracts all objects toward each other.
This constant pulling and pushing is what keeps the Earth and the moon in orbit. The Earth is constantly pulling the moon towards it with gravity and the moon is constantly pulling away with inertia.
Section 3: Phases, Eclipses, and Tides
What causes the phases of the moon?
The different shapes of the moon you see in the sky are phases.
The phases of the moon are caused by the different light amounts shown on the moon from the Sun and the position of the moon around the Earth.
The phases of the moon you see depends on how much of the sunlit side of the moon faces the Earth.
What are solar and lunar eclipses?
A solar eclipse happens when a new moon blocks your view of the sun.
A lunar eclipse happens when the Earth is directly between the sun and a full moon.
When the moon passes directly between the Earth and the sun, blocking sunlight from Earth, a solar eclipse occurs.
When Earth blocks sunlight from the moon, a lunar eclipse occurs.
what causes the tides?
The tides are caused by the different amounts of moon's gravity pulling on different parts of Earth.
The greatest difference between consecutive low and high tides is called a spring tide.
A tide with the least difference between consecutive low and high tides is called a neap tide.
A spring tide is caused by the combined gravity of the sun and the moon pulling in the same direction.
A neap tide is caused by the sun's pull at a right angle to the moon's pull off gravity.
Section 4: Earth's Moon
What features are found on the moon's surface?
The moon's surface has features that include maria, craters, and highlands.
Galileo named the spots on moon's surface that are dark, flat areas maria because that is the Latin word for sea and he wrongly thought that they were seas. The maria are actually hardened lava rock.
Craters are large round pits on the surface of the moon. Craters are made by meteoroids crashing into the moon's surface.
The lightly colored features on the moon's surface are mountains, or highlands.
What are some characteristics of the moon?
The moon is airless and dry. The moon is small and has variations in surface temperature.
The moon is 3,476 kilometers in diameter and has one-eightieth as much mas as Earth. The moon's average density is similar to Earth's outer layers density.
On the moon's surface, temperatures range from 130 degrees Celsius to -180 degrees Celsius because kit has no atmosphere.
The moon has no liquid water, but it may have large patches of ice towards its poles.
How did the moon form?
The origin of the moon best fits the collision-ring theory.
About 4.5 billion years ago, the solar system was full of rocky debris, some even the size of small planets! One of these "planets" collided with the Earth to form the moon. pieces of the Earth shot out and formed a ring. Gravity caused the ring to combine, forming the moon.