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# Section 1 Earth in Space

## How does Earth move in space?

Rotation and revolution are the two major ways that Earth moves around in space.

Earth's axis is the imaginary line that passes through Earth's center and North and South Poles. Earth rotates on its axis. This rotation causes night and day.

Earth revolves around the sun, meaning that while it is spinning on its axis, it is also moving in a circle around the sun. One revolution around the sun takes 365.25 days.

## What causes the cycle of seasons on Earth?

The tilt of Earth's axis causes the seasons. During summer in the Northern Hemisphere, it is winter in the Southern Hemisphere. This is because when it is summer in the Northern Hemisphere, Earth's axis is tilted toward the sun, giving it more direct sunlight then the Southern Hemisphere. But when the axis is tilted away from the sun, the Southern Hemisphere gets more direct sunlight causing it to be summer there, but winter up North. And the same goes for fall and spring.

# Section 2 Gravity and Motion

## What determines the strength of the force of gravity between two objects?

Gravity is the force that attracts all objects toward each other.

The strength or the force of gravity between two objects is determined by the mass of the objects and the distance between them.

Mass is the amount of matter in an object. If mass increases, force increases, too. If distance increases, force decreases.

## What two factors combine to keep the moon in orbit?

Isaac Newton concluded that inertia and gravity keep the moon in orbit around the Sun.

Inertia is the tendency of an object to resist a change in motion.

Gravity pulls the moon toward the Earth, keeping it from going in straight line. However, the moon keeps moving ahead because of its inertia.

# I'm having a star-gazing camp out! Please RSVP below.

9 people are going
Invite Friends
9 going1 maybe2 no
B_Knapik 2 years ago

Gazing is like awesome!

mgebeau 2 years ago
ibenz (+5) 2 years ago

The party don't start 'til I walk in.....

Alyssa Santora 2 years ago
? bwood 2 years ago

Im only coming if there is pizza...

BBell 2 years ago

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Macey Chamberlin Organizer

sorry, i'm busy that day.

# Section 3 Phases, Eclipses, and Tides

## What causes the phases of the moon?

The phases of the moon are caused the positions of the moon, Earth, and Sun.

One rotation of the moon on its axis takes the same amount of time as it takes for it to revolve around the Earth once. There for, a day and a year on the moon are the exact same length. Because of this, the same side of the moon is always facing Earth. The phases of the moon depends on how much sunlit side of the moon you can see from Earth.

## What are solar and lunar eclipses?

An eclipse occurs when the moon's shadow hits Earth or Earth's shadow hits the moon.

A solar eclipse is when the moon passes directly between Earth and the Sun.

A lunar eclipse is when 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 different parts of Earth.

# Section 4 Earth's Moon

## What features are found on the moon's surface?

Maria, craters, and highlands are all features on the moon's surface.

Maria are the dark and flat areas on the moon. Galileo thought that these maria were oceans. They are formed from hardened rock from lava flows 3 and 4 billion years ago.

Craters are large round pits on the Earth's surface. Some craters are hundreds of kilometers in diameter. Scientists now know that these craters were caused by meteoroids that impacted the moon. Scientists have found that most craters were formed before the maria.

Highlands are mountains on the moon. These mountains cast shadows on the moon's surface. These cover much of the moon's surface.

## What are some characteristics of the moon?

The moon is dry and airless. The moon is small compared to the Earth and has large surface temperature variations.

The moon is 3,476 kilometers in diameter; about one fourth of the Earth's diameter.

Temperatures on the moon range from 130 degrees Celsius in direct sunlight to -180 degrees Celsius at night. The moon's temperatures vary so much because it has no atmosphere.

The moon has no liquid water. However, there may be large patches of ice near its poles.

## How did the moon form?

There have been many suggested theories as to how the moon formed. Some say that the moon was formed elsewhere in the solar system and was captures by Earth's gravity. Or was it formed at the same time as Earth, right by its side?

The most popular theory is the collision-ring theory. This theory states that a planet-sized object collided with Earth, and the moon was formed. Material from both the object and Earth formed a ring around Earth, and was eventually compiled by gravity, which made the moon. This theory best describes the origin of the moon.

## This is a pretty cool video

### Comment Stream

2 years ago
0

Great pictures! good for understanding.

2 years ago
0

Love the gifs! Your tackk is perfect

2 years ago
0

2 years ago
0

Your animations truly help with the understanding of this lesson. Also, cool pics macey

2 years ago
0

wow, tons of info and really cool pics!!!

2 years ago
1

AWESOME!