The Earth – Sun The Earth – Sun RelationshipRelationship

Core ContentCore Content

• SC-04-2.3.4 SC-04-2.3.4

• Students will identify patterns, Students will identify patterns, recognize relationships and draw recognize relationships and draw conclusions about the Earth-Sun conclusions about the Earth-Sun system by interpreting a variety of system by interpreting a variety of representations/models (e.g., representations/models (e.g., diagrams, sundials, distance of sun diagrams, sundials, distance of sun above horizon) of the sun’s apparent above horizon) of the sun’s apparent movement in the sky.movement in the sky.

ObjectiveObjective

• Be able to explain patterns that Be able to explain patterns that occur within the Earth-sun system.occur within the Earth-sun system.

Essential QuestionEssential Question

• How can we determine How can we determine patterns/relationships within the patterns/relationships within the Earth-sun system using models? Earth-sun system using models?

VocabularyVocabulary

• Rotation – describes the way earth Rotation – describes the way earth spins on its axis (causes day and spins on its axis (causes day and night).night).

• Revolution – describes how earth Revolution – describes how earth circles the sun (takes 1 year).circles the sun (takes 1 year).

• Axis – an imaginary line that runs Axis – an imaginary line that runs between earth’s north and south between earth’s north and south polespoles

Earth’s RotationEarth’s Rotation

• Earth spins on its axis Earth spins on its axis like a top.like a top.

• It takes one full day for It takes one full day for earth to make one full earth to make one full spin on its axis.spin on its axis.

• This causes day and This causes day and night.night.

• Explains why the sun Explains why the sun and other stars appear and other stars appear to move across the to move across the sky.sky.

Earth’s TiltEarth’s Tilt• Earth’s Axis is tilted Earth’s Axis is tilted

23 ½ degrees.23 ½ degrees.• If Earth’s axis was If Earth’s axis was

upright, our days upright, our days would always be the would always be the same length and we same length and we would have no would have no seasons. seasons.

• Earth’s tilt causes Earth’s tilt causes the seasons and the seasons and longer or shorter longer or shorter days. days.

Earth’s RevolutionEarth’s Revolution

• All planets orbit the sun because of gravitational pull.All planets orbit the sun because of gravitational pull.• Earth’s orbit around the sun is called its revolution.Earth’s orbit around the sun is called its revolution.• Earth’s orbit is elliptical, not circular.Earth’s orbit is elliptical, not circular.• As earth revolves around the sun, the seasons change.As earth revolves around the sun, the seasons change.• It takes earth 365 days (or 1 year) to revolve the sun once. It takes earth 365 days (or 1 year) to revolve the sun once.

The Earth/Sun SystemThe Earth/Sun System

Earth’s RevolutionEarth’s Revolution

Today’s ticket out the Today’s ticket out the door…door…

• What is rotation?What is rotation?

• What is revolution?What is revolution?

• What would happen if earth was not What would happen if earth was not tilted on its axis?tilted on its axis?

• Describe what causes day and night.Describe what causes day and night.

• Explain why seasons change. Explain why seasons change.