Earth’s Motion in SpaceEarth’s Motion in SpaceMarch 1, 2011March 1, 2011

Essential Question: How does the position of the Earth in the solar system affect our

conditions on Earth? (day and night/seasons)

IndicatorsIndicators

(B. 22) Explain the cause of day and night based on the rotation of Earth on its axis .

(B. 24) Describe the relationship of the seasons to the Earth’s revolution around the sun .

Predict VocabularyPredict Vocabulary

RevolutionRotationAxis

Actual Definition RotationActual Definition Rotation

The action of turning about on an axis.

Example: The Earth turning on its axis in a counterclockwise direction thus creating the day and night cycle.

Actual Definition of RevolutionActual Definition of Revolution

The action of a celestial body going around an orbit

Example: Earth orbiting around the sun on its axis in a counterclockwise direction thus giving us the seasons

Actual Definition of AxisActual Definition of Axis

The real or imaginary straight line through the center of an object around which it rotates

Example: The imaginary line running through two poles, around which the Earth rotates

Direct Sunlight/Indirect SunlightDirect Sunlight/Indirect Sunlight

Direct Sunlight=when the sun hits the part of the Earth and gives its most intense rays

Example: North America in JulyIndirect Sunlight: when the sun hits the

part of the Earth and gives partial sun rays!

Example-North America in December!

Pre Lab QuestionsPre Lab Questions

Why do we have day and night on Earth?

Why do we have seasons?

Day and Night AnswerDay and Night Answer

We have day and night because of the position of the Earth and the Sun in space. The sun is a star in space. The Earth is a planet that is shaped like a sphere and rotates on its axis. During the Earth’s rotation, only half of its body can face the sun at one time. The half that happens to be rotated towards the sun is experiencing day where the half that is facing away from the sun is experiencing night.

Day and Night Response Day and Night Response RubricRubric5 points5 points

Position of Earth and Sun in space create the day and night cycle

Earth rotates on an axisOnly half of the sphere shaped Earth can

face the sun at one timeThe half that faces the sun experiences

dayThe half that faces away from the sun

experiences night

What are the reasons for the What are the reasons for the Seasons?Seasons?

Answer on a sheet of paper!

Seasons AnswerSeasons Answer

We have seasons on Earth because of the position of the Earth and the Sun in space. The sun is a star. The Earth is a sphere that is tilted on an axis. The Earth’s axis is always tilted in the same direction as it revolves around the sun. Therefore, the sun’s rays hit the Earth at different angles during the Earth’s revolution the Sun. The axis that is facing towards the sun receives direct sunlight (absorbs more light) and experiences summer while the axis that is facing away from the sun receives indirect sunlight (scattered sun’s rays) and experiences winter.

Seasons Response RubricSeasons Response Rubric7 Points7 Points

The position of Earth and Sun in space dictate the seasons

The sun is a star that is still and the Earth is a sphere that is tilted on an axis

Earth’s axis is always tilted in the same direction as it revolves around the sun

Sun’s rays hit the Earth at different anglesAxis that faces the sun has summerAxis that faces away from the sun has winterWhen the Earth’s axis is not tilted towards or

away from the sun, fall and spring occur

Post Lab QuestionsPost Lab Questions

Why do we have day and night?Why do seasons occur?

Day and Night AnswerDay and Night Answer

We have day and night because of the position of the Earth and the Sun in space. The sun is a star that is relatively still in space. The Earth is a planet that is shaped like a sphere and rotates on its axis. During the Earth’s rotation, only half of its body can face the sun at one time. The half that happens to be rotated towards the sun is experiencing day where the half that is facing away from the sun is experiencing night.

Day and Night Response Day and Night Response RubricRubric5 points5 points

Position of Earth and Sun in space create the day and night cycle

Sun is still and the Earth rotates on an axis

Only half of the sphere shaped Earth can face the sun at one time

The half that faces the sun experiences day

The half that faces away from the sun experiences night

Seasons AnswerSeasons Answer

We have seasons on Earth because of the position of the Earth and the Sun in space. The sun is a star that is relatively still in space. The Earth is a sphere that is tilted on an axis. The Earth’s axis is always tilted in the same direction as it revolves around the sun. Therefore, the sun’s rays hit the Earth at different angles during the Earth’s revolution the Sun. The axis that is facing towards the sun receives direct sunlight (absorbs more light) and experiences summer while the axis that is facing away from the sun receives indirect sunlight (scattered sun’s rays) and experiences winter. When the Earth’s axis is not tilted towards or away from the sun, direct sunlight hits the equator creating similar conditions in both hemispheres so Spring and Fall occur.

Seasons Response RubricSeasons Response Rubric7 Points7 Points

The position of Earth and Sun in space dictate the seasons

The sun is a star that and the Earth is a sphere that is tilted on an axis

Earth’s axis is always tilted in the same direction as it revolves around the sun

Sun’s rays hit the Earth at different anglesAxis that faces the sun has summer-Direct

Sunlight (absorbs the sun’s rays)Axis that faces away from the sun has winter

(indirect sunlight (scattered sunlight)When the Earth’s axis is not tilted towards or

away from the sun, direct sunlight hits the equator creating similar conditions in both hemispheres so Spring and Fall occur.

HorizonHorizon

The place where the Earth and the sky look like they meet.

SunriseSunrise

The apparent rising of the sun above the horizon, the time when the upper most portion of the sun’s disc appears above the horizon

(this is really caused by the earth’s rotation towards the sun)

SunsetSunset

the apparent descent of the sun below the horizon, the time when the upper most portion of the sun’s disc disappears below the horizon

This is really the Earth rotating away from the sun!!

OrbitOrbit

The path followed by an object in its revolution around another body.

Direct SunlightDirect Sunlight

Sunlight that reaches the surface of the Earth at angles greater than 45 degrees from the horizon

Sun should be in this position!

Equinox (Vernal and Autumnal)Equinox (Vernal and Autumnal)

When day and night are of equal length anywhere in the world. Equinox literally means “equal night.”

Solstice (Winter and Summer)Solstice (Winter and Summer)

The moment when the Earth’s axis is leaning at its maximum (23.5˚) towards or away from the sun; on or about June 21 and December 21.

Compass RoseCompass Rose

Compass Rose:A circle showing the

principal directions printed on a map or chart.