Sun Earth Moon System

Sun, Earth, and Moon

5.8D Identify and compare the physical characteristics of the Sun, Earth, and Moon.

The sun is the center of our solar system.

We have 8 planets in our solar system that move around the sun.

Multiple Choice

The center of our solar system is the-

• Moon

• Sun

• Earth

• Satellite

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A planet is ...

a large body of rock or gas.

Our solar system also contains...

• Moons

• Asteroids

• Comets

Orbit

Each planet moves around the sun in a curved path called an orbit.

Multiple Choice

What is orbit?

• spinning around

• reflecting sun's light

• the path an object takes around another object

• a straight path into space

Gravity

The sun's gravity pulls planets towards it and keeps each planet in orbit.

Multiple Choice

What keeps the planets in our solar system in orbit?

• the sun's energy

• the natural satellites of the planets

• the gases that make the sun

• the sun's gravitational pull

There are eight planets in our solar system. They are divided into two groups.

Inner Planets

Outer Planets

Inner planets are closer to the sun.

• Mercury

• Venus

• Earth

• Mars

Outer planets are farther from the sun.

• Jupiter

• Saturn

• Uranus

• Neptune

The International Astronomical Union/Martin Kornmesser, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

The sun, Earth, and moon are three different types of objects.

The Sun

A star

The Sun

• A star made of mostly hydrogen and helium gases held together by gravity

• Has a core

• Rotates (Equator rotates faster than its poles)

• Largest thing in our solar system but medium size for a star

• Less dense than Earth

• Generates a lot of energy in a process called fusion

• Takes between 10,000 to 170,000 years for Sun's energy to travel from its core to its surface, but only 8.33 minutes for that energy to travel from the sun to Earth

The Sun (continued)

• The energy from the sun travels to Earth as electromagnetic radiation

• This radiation includes the visible light we see

• Its light reaches the moon

• It is about 109 times wider than Earth

• Has sun spots and solar flares that shoot out into space

• Diameter is 1, 391,016 km

• Average temperature 5,500°C

Multiple Choice

Which occurs during fusion?

• Sunspots develop on the sun

• the nuclei of the sun's atoms join together

• the sun's energy travels to Earth

• the sun's light reflects off the moon

Multiple Choice

Which direction does the sun appear to move across the sky?

• The sun rises in the east and sets in the west.

• The sun rises in the west and sets in the east.

• The sun rises in the north and sets in the south.

• The sun rises in the south and sets in the north.

Day and Night

The sun appears to rise in the east and set in the west. The sun is not really moving. The sun stays were it is and spins or rotates. It is the Earth's rotation that makes the sun appear to move. Earth rotates on its axis once every 24 hours. The Earth's rotation also makes the moon and the stars appear to move. This rotation causes day and night. When one side of the Earth is in the dark of night, the other side experiences the light of day.

Seasons

Earth's tilt on its axis as it revolves around the sun causes some areas to experience seasonal climate. Earth's axis points towards the sun in summer. During fall and spring, the Earth's axis points neither towards or away from the sun. During winter, Earth's axis points away from the sun.

The Earth

Image by Arek Socha from Pixabay

The Earth

• Has three layers: crust (outer layer), mantle (solid and liquid rock called magma beneath the crust), and core (the center)

• Rotates on its axis every 24 hours

• Consists mostly of solids and liquids

• Four times denser than the Sun

• Revolves counterclockwise around the sun (Orbit takes about 365 days)

• Has craters from astroids striking some 4 billion years ago

• Core is mostly made of melted iron, but its too deep to test (6,000 kilometers below the surface)

The Earth (continued)

• Called the blue planet because most of its surface is covered by water

• Has a thick layer of atmosphere made of nitrogen and oxygen

• Diameter of 12,742 km

• Composition is mainly iron, oxygen, silicon, and magnesium

• Surface temperatures range from -88°C to 58°C

• Considered a satellite of the sun because it revolves around it

Multiple Choice

What causes day and night?

• The orbit of Earth

• The revolution of Earth

• The rotation of Earth

• The moon orbiting Earth

Multiple Choice

Which statement about Earth is true?

• Earth is tilted on its axis.

• Earth is straight up and down on its axis.

• Earth does not move.

• Earth's axis is horizontal.

Multiple Choice

How long does it take for Earth to rotate on its axis?

• 365 days

• 1 year

• 8 hours

• 24 hours

Multiple Choice

How long does it take for Earth to revolve around the sun?

• about 365 days

• 24 hours

• 8 hours

• 29 days

The Moon

Earth's Only Natural Satellite

The Moon

• Revolves counterclockwise around the Earth (Orbit)

• Orbit takes a little longer than 27 days

• Rocky like Earth

• Denser than the Sun but less dense than Earth

• Has craters formed by asteroids striking its surface some 4 billion years ago

• 3,475 km in diameter, tiny when compared to the sun

• Scorching hot temperatures during the day and freezing cold at night

The Moon (continued)

• Has mountains and flat plains like Earth

• Composed of mainly oxygen, silicon, magnesium, and iron

• No atmosphere

• Temperatures range from -233°C to 123°C

• Considered a satellite of the Earth because it revolves around it

Multiple Choice

The moon is a -

• Sun

• Planet

• Satellite

• Star