Earth, Moon, and Sun
Earth in Space
How Does Earth Move Through Space?
The Earth's seasons are caused by the tilt of Earth's axis and it orbiting around the sun. Most places that are outside the polar and tropic regions have distinct seasons such as winter, summer, spring, and autumn. It is warmer year round near the equator because there is more direct sunlight hitting it than the poles where it is more spread out. If Earth's axis was straight up and down then there would be no seasons.
What causes Earth's seasons?
Earth moves through Earth in two big ways and the are rotation and revolution. An imaginary line passes through Earth through its north and south poles and it is called the axis. Earth spins on its axis and this is called rotation. Earth's rotation causes day and night. The Earth also travels around the sun and this is called a revolution. The Earth follows a path called orbit as it goes around the sun. Earth's orbit isn't circular, it is more of an elongated circle or eclipse.
Gravity and Motion
What Determines the Strength of Gravity Between two Objects?
Gravity is a force the attracts all objects in the universe. This is the law of universal gravity. The strength of the force of the gravity is determined by the masses of the objects and the distance between the objects. The closer the objects are, the stronger the pull. As they get farther away the force of gravity gets weaker. The strength of the gravity is also affected by the mass of an object, the larger mass of an object the stronger the force of gravity, the less mass an object has, the weaker the force of gravity.
What Factors Keep the Earth and Moon in Orbit?
Gravity and inertia keep the Earth and the moon in there places. The Earth and the sun are constantly pulling on each other, inertia is the factor that keeps them from colliding with each other. Inertia is the tenancy of an object to resist a change in motion. Earth's moon would go in a straight line but the force of gravity from Earth keeps it in a constant orbit around the Earth.
Phases, Eclipses, and Tides
What Causes the Phases of the Moon?
The moon reflects light from the sun and the amount of light that is reflected is determined by the position of the moon around the Earth. The changes are caused by the relative positions of the Earth, moon, and sun.
What are Solar and Lunar and Eclipses?
When an object in space comes between the sun and a third object, it cast a shadow and that is called an eclipse.. An eclipse is when the moon's shadow hits Earth or Earth's shadow hits the moon. There are two types of eclipses, lunar and solar. A solar eclipse occurs when the moon passes in between the Earth and the sun and blocks out light. A lunar eclipse is when the Earth blocks sunlight from reaching the moon.
What Causes the Tides?
The tides are caused by the differences in how much the moon's gravity pulls on different parts of the Earth. The sun's gravity also pulls on Earth's waters. The sun, moon, and the Earth are nearly in a straight line