Sun & Earth: Earth rotates on a tilted axis

& orbits the Sun!

MRS. GIANELOSLesson 2.1 SPACE SCIENCE

GRADE 8

What you will learn today…

• What causes day & night?

• What percent of the earth is always lit by the sun?

• How many days does it take for the Earth to revolve around the sun?

• Why do we have seasons?

• What is an Equinox and Solstice?

The Earth Rotates: • turns on its imaginary axis counterclockwise every

24 hours or 1 day,AXIS OF ROTATION =23 degreesPoles are end of axis, equator is halfway

Sun shines on one side of Earth only

*LIGHT side is DAY*Dark side is NIGHT|

night moves west

LET’S REVIEW • The rotation of the Earth on its

axis causes-• A days

• B months

• C seasons

• D years

What is rotation? (define)

http://www.cs.sbcc.cc.ca.us/~physics/flash/LengthofDay.swf

Rotation causes day & night.

• Rotation is the turning or spinning of the Earth in one place on its imaginary axis.

• Rotation of the earth on its axis causes day & night. (answer A).

Earth’s tilted axis & orbit cause seasons.SEASONS: patterns of

temperature change and other weather trends over a year

SEASONS OCCUR BECAUSE:

**the amount of sunlight hitting an area changes because of Earth’s tilt

Which of these is caused by the turning of the Earth?

• F Summer and winter

• G Stars

• H Day and night

• J Moon phases

Earth Science Question:

• Which of these shows the location of a polar ice cap?

• Which of these shows the location of the equator?

The revolution of the Earth around the sun

• Takes 365 days

or one year.

Due to the tilt of the Earth’s axis during revolution, the Earth experiences seasons.

Earth’s orbit is close to a circle shape

http://esminfo.prenhall.com/science/geoanimations/animations/01_EarthSun_E2.html

The revolution of the Earth around the Sun takes-

• A a day & night or 12 hours

• B a week or 7 days

• C a month or 29-31 days

• D a year or 365 days

Seasons

Equinox: sunlight shines evenly on Northern & Southern HemispheresSolstice: area of sunlight is at it’s maximum in one of the hemispheres