Earth, Sun, Moon, & Stars

Earth, Sun, and Moon, and Stars!!!

Movement in Space

• Everything in our solar system is in constant motion.

• The force that keeps everything moving and keeps it located where is should be is gravity.

• Due to everything having gravity and attracting each other, everything stays in constant motion around each other.

• This is called the Law of Universal Gravitation: every object in the universe attracts every other object.

Geocentric vs. Heliocentric Models

• Geocentric model: was a model where ancient astronomers believed that Earth was as the center of the solar system. They believed that everything including stars, planets and the sun revolved around Earth.

• Heliocentric model: after astronomers learned more about the solar system they developed another model called the heliocentric model. This model placed the sun at the center of the solar system not Earth. Therefore everything revolved around the sun including planets, and moons.

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The Seasons

• We all know that Earth has seasons. They are Winter, Spring, Summer and Fall.

• The reason that we have seasons is because Earth does not sit straight up and down in space, it is tilted.

• This tilt causes different amounts of the sun's energy to hit us at different times of the year.

• When we are in Summer we are tilted toward the sun, so we get more of the suns energy and therefore we are warmer.

• In Winter we are tilted away from the sun so we get less of the suns energy and therefore we are cooler.

Poll

Which model, Geocentric or Heliocentric, is the correct model of the solar system?

• Geocentric Model

• Heliocentric Model

Earth's Movement in Space

• Earth moves in two ways. It rotates and it orbits.

• Rotation: happens on Earth's axis or the invisible line that goes through the middle of Earth from the top to the bottom, or North and South Poles.

• Orbit: Earth orbits around the sun. While Earth is rotating on it's axis it causes it to want to move outward. Since the suns gravity is so great it holds the earth in its location and causes it to orbit around the sun.

Open Ended

What are the two ways that the earth moves?

Earth's Seasons

• Notice how the North Pole is always pointing in the same direction.

• This tilt is the reason for our seasons.

• In Summer and Spring we in North America are facing the sun almost head on.

• And in the winter and fall we are facing more away from the sun.

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Moon Phases

• Just like the earth, the moon is rotating on it's own axis. As it it is rotating it revolves around the earth.

• The moon rotates on its axis at the same rate as it revolves around the earth. There for the moon has phases.

• The reason we see the different phases of the moon depends on how much of the light from the sun is reflected off of the moon due to the shadow of the earth.

Multiple Choice

What causes the moon to have phases?

• Earth's Rotation and Revolving

• Sun's Rotation and Revolving

• Moon's Rotation and Revolving

• All of the above

Solar Eclipse and Lunar Eclipse

• Solar: occurs when the moon passes directly between Earth and the sun, blocking the suns light. Only happens during daylight hours.

• Lunar: occurs during a full moon when Earth is directly between the moon and the sun. Earth blocks sunlight from reaching the moon. Only happens during a full moon and only at night.

Multiple Select

What happens during a Solar Eclipse?

• Moon blocks the sun

• Earth blocks the Sun

• Happens during the day

• Happens during the night

• Happens during full moon.

Tides

• Tides are caused from the gravitational pull from the moon. (Law of Universal Gravitation)

• As the moon pulls on the earth it causes a oval bulge on opposite sides of the earth. This causes our high tides.

• Perpendicular to the high tides and the pull of the moon we have low tides.

• Due to Earth rotating on its axis we have two high tides and two low tides each day. Earth rotates in and out of the high tide and in and out of the low tides.

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Types of Tides

• There are two types of tides

• Spring tide: This is when the moon and sun are in direct line of each other. This pull from both objects create higher than normal high tides called Spring Tides.

• Neap tide: these are the normal tides that we have when the moon and sun are out of line with each other.

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Open Ended

What causes the tides on Earth?

Open Ended

There are two types of tides on Earth, what are they and what causes them?

Astronomy

• Astronomy is the study of the universe.

• Universe is everything that exists; Ex: Earth, planets, stars, and all of space

• Telescope is a device that collects light and magnifies images to make distant objects appear closer, larger, and brighter.

2 types of telescopes

• Refracting: uses lenses to gather light from a faraway object and magnify its image. the light is bent

• Reflecting: visible light reflects off a series of two or more mirror, which amplify the image before it reaches lenses in the eyepiece

• MOST telescopes are reflecting cause its easier to build large mirrors.

Multiple Choice

What type of telescope use mirrors?

• reflecting telescope

• refracting telescope

Multiple Choice

Astronomy is the study of:

• the stars

• the planets

• the universe

• Earth

Multiple Choice

When the Northern Hemisphere is tilted away from the Sun, we have the season of:

• Summer

• Winter

STARS... What are they?

• The only light producing body in space.

• ball of gases that are continuously going through nuclear fussion

• only one in our solar system

​constellations are....

​a collection of stars in a pattern seem to move West across the sky during the seasons.... but... they do not move, Earth does!!

The sun is the only star in our solar system and is closer to Earth than any other star.

that is why.....

It appears the largest

It gives us the most light

It is the largest body in our solar system

It has the most mass and therefore the most gravity!

Multiple Select

Check all that apply.... Stars are:

• light producers

• dark

• small

• the sun

Poll

constellations are stars in our solar system......

• true

• false

Multiple Choice

Why do other stars appear so much smaller than the sun?

• They are much smaller

• They are so far away

• They are not as bright

• They are dwarf stars

Remember, when determining how HOT a star is, color matters!

RED stars are the coolest

Yellow and Orange stars are moderate

Blue and White stars burn the hottest