Moons Orbit Around Earth

Chapter 22:
The Sun-Moon-Earth System

Learning Objective:
Explain the patterns of the sun, moon, and stars as seen from Earth, monthly patterns of the moon, and eclipses.

https://www.youtube.com/watch?v=2HoTK_Gqi2Q

Video: Sun 101

Guide Questions

Explain what you know about the Sun and Moon.
Does the moon have its light? Why or why not?
Is the Sun considered a star? Why or why not?

The Sun's Path in the Sky

• The sun APPEARS to rise in the East and set in the West due to the rotation of the Earth.

• Day and night LENGTH varies depending on where you are on Earth, and the time of year, but they always add up to 24 hours.

Multiple Choice

What causes the sun to appear to rise in the East and set in the West?

• The tilt of the Earth on its axis

• The rotation of the sun

• The rotation of the Earth

• The orbit of the Earth around the Sun

The Stars' Path in the Sky

• Stars appear to rise in the East and set in the West due to Earth's rotation.

• We see different constellations over the course of the year due to Earth's tilt and our movement around the sun.

• We can only see stars at night because the sun is so bright it blocks their light.

Multiple Select

Which statement(s) is/are true?

• Stars appear to move from East to West

• The stars change location over the course of the year.

• Certain stars become visible at different times of the year.

• The same stars are seen in both hemispheres.

The Moon's Path in the Sky

• The moon appears to rise in the East and set in the West due to Earth's rotation.

• The time it takes the moon to revolve around Earth and turn once on its own axis is about the same. This is why we always see the SAME side of the moon.

https://www.youtube.com/watch?v=6AviDjR9mmo

Video: Moon 101

Multiple Choice

True for False: It takes about a year for the moon to make it all the way around Earth.

• True

• False

Multiple Choice

The moon rises and sets at different times each day because of

• the time it takes for it to orbit the sun.

• the time it takes it to revolve around the Earth.

• the gravitational pull of the Earth and Sun.

Moon Phases

• One half of the moon is always being lit by the sun. The other half is dark.

• We see different "phases" due to our perspective.

• The phases repeat in a regular pattern since the Moon is constantly revolving around Earth.

Open Ended

Why is this diagram inaccurate? (*hint: Would we see a full moon?)

Multiple Choice

A new moon is in the sky during the day, but can't be seen due to the sun's brightness.

• True

• False

Eclipses

• A SOLAR ECLIPSE happens when the moon gets between the Sun and Earth, blocking out the Sun's light. (SME)

• A LUNAR ECLIPSE happens when the Earth gets between the Sun and Moon and casts a shadow on the Moon. (SEM)

Lunar Eclipse: https://www.youtube.com/watch?v=LH-aSizsx1o

Solar Eclipse: https://www.youtube.com/watch?v=E6OtLfszaVI

Video: Solar and Lunar Eclipse

1.Differentiate partial and total lunar eclipse.
2. What causes "blood moons"
3. Differentiate partial and total solar eclipse.
4. Is it safe to look directly at a solar eclipse? Why or why not?

Guide Questions

A Little About Shadows

• Shadows are not one solid shade.

• The UMBRA is the darkest part of a shadow. Here people will experience a TOTAL ECLIPSE.

• The PENUMBRA is the lighter part of a shadow. Here people will experience a PARTIAL ECLIPSE

Multiple Choice

The darkest part of a shadow.

• umbra

• penumbra

• antumbra

• abracadabra

Multiple Choice

Lighter part of a shadow.

• umbra

• penumbra

• umbrella

• a ghost

Multiple Choice

More area on Earth will be cast in the umbral shadow of an eclipse than the penumbral shadow.

• True

• False

Types of Solar Eclipses

• Total Eclipse: When the sun appears to be completely covered by the Moon. Only a bright halo remains.

• Annular Eclipse: When the Moon is farther from Earth in its orbit, so it doesn't completely cover the Sun (the umbra doesn't reach Earth)

• Partial Eclipse: Seen from the penumbra.

Types of Lunar Eclipses

• Total Lunar Eclipse: When the moon passes through Earth's umbra. It appears orange.

• Partial Lunar Eclipse: When the moon partially passes into the umbra.

• Penumbral Lunar Eclipse: When the moon is in Earth's penumbra; it will appear more dim than usual.

Timing of Eclipses

• We don't see eclipses each month because the Moon's orbit around Earth is not on the same plane as Earth's orbit around the Sun.

• The Moon's orbit is "tilted" relative to the Earth and Sun.

Multiple Choice

Which diagram best shows how the moon’s appearance will change during a typical month?

• A

• B

• C

• D

Multiple Choice

Which list represents the position of Earth, the sun, and the moon during a full moon?

• Earth, sun, moon

• sun, moon, Earth

• moon, sun, Earth

• sun, Earth, moon

Multiple Choice

What would happen if the time it took for Earth to make one rotation around its axis increased?

• A day would be shorter.

• A day would be longer.

• A year would be shorter.

• A year would be longer.

Multiple Choice

Which phrase best defines the orbit of Earth?

• the position in space of Earth at a certain time

• the distance from the sun to Earth at any point

• the spin of Earth on its axis as it moves forward

• the path Earth travels as it revolves around the sun

Multiple Choice

As it rotates, how long will it take for the Earth to be in this same position again?

• 12 hours

• 24 hours

• 1 week

• 1 month

Multiple Choice

The diagram is showing which process?

• waxing

• waning

• washing

• wailing

Multiple Choice

The diagram is showing which process?

• waxing

• waning

• warming

• wanting

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.

• 
  

Poll

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

• Geocentric Model

• Heliocentric Model

The Seasons

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

• 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 sun's energy and therefore we are cooler.